]> wimlib.net Git - wimlib/blobdiff - src/dentry.c
Timestamp printing UTC
[wimlib] / src / dentry.c
index 50351fb0d3d57b0a592e4cd03e419ce721b663e0..8a285e25a0b6f4590a4efac5d3e622eced0e8b42 100644 (file)
  * along with wimlib; if not, see http://www.gnu.org/licenses/.
  */
 
-#include "wimlib_internal.h"
+#include <errno.h>
+#include <sys/stat.h>
+#include <time.h>
+#include <unistd.h>
+
 #include "dentry.h"
 #include "io.h"
-#include "timestamp.h"
 #include "lookup_table.h"
 #include "sha1.h"
-#include <errno.h>
-#include <unistd.h>
-#include <sys/stat.h>
+#include "timestamp.h"
+#include "wimlib_internal.h"
 
 /*
  * Returns true if @dentry has the UTF-8 file name @name that has length
@@ -52,14 +54,48 @@ static bool dentry_has_name(const struct dentry *dentry, const char *name,
        return memcmp(dentry->file_name_utf8, name, name_len) == 0;
 }
 
+static u64 __dentry_correct_length_unaligned(u16 file_name_len,
+                                            u16 short_name_len)
+{
+       u64 length = WIM_DENTRY_DISK_SIZE;
+       if (file_name_len)
+               length += file_name_len + 2;
+       if (short_name_len)
+               length += short_name_len + 2;
+       return length;
+}
+
+static u64 dentry_correct_length_unaligned(const struct dentry *dentry)
+{
+       return __dentry_correct_length_unaligned(dentry->file_name_len,
+                                                dentry->short_name_len);
+}
+
+/* Return the "correct" value to write in the length field of the dentry, based
+ * on the file name length and short name length */
+static u64 dentry_correct_length(const struct dentry *dentry)
+{
+       return (dentry_correct_length_unaligned(dentry) + 7) & ~7;
+}
+
+static u64 __dentry_total_length(const struct dentry *dentry, u64 length)
+{
+       for (u16 i = 0; i < dentry->num_ads; i++)
+               length += ads_entry_total_length(&dentry->ads_entries[i]);
+       return (length + 7) & ~7;
+}
+
+u64 dentry_correct_total_length(const struct dentry *dentry)
+{
+       return __dentry_total_length(dentry,
+                                    dentry_correct_length_unaligned(dentry));
+}
+
 /* Real length of a dentry, including the alternate data stream entries, which
  * are not included in the dentry->length field... */
 u64 dentry_total_length(const struct dentry *dentry)
 {
-       u64 length = (dentry->length + 7) & ~7;
-       for (u16 i = 0 ; i < dentry->num_ads; i++)
-               length += ads_entry_length(&dentry->ads_entries[i]);
-       return length;
+       return __dentry_total_length(dentry, dentry->length);
 }
 
 /* Transfers file attributes from a `stat' buffer to a struct dentry. */
@@ -78,28 +114,39 @@ void stbuf_to_dentry(const struct stat *stbuf, struct dentry *dentry)
        else
                dentry->hard_link = (u64)stbuf->st_ino |
                                   ((u64)stbuf->st_dev << (sizeof(ino_t) * 8));
+       /* Set timestamps */
+       dentry->creation_time = timespec_to_wim_timestamp(&stbuf->st_mtim);
+       dentry->last_write_time = timespec_to_wim_timestamp(&stbuf->st_mtim);
+       dentry->last_access_time = timespec_to_wim_timestamp(&stbuf->st_atim);
 }
 
 
-/* Makes all timestamp fields for the dentry be the current time. */
+/* Sets all the timestamp fields of the dentry to the current time. */
 void dentry_update_all_timestamps(struct dentry *dentry)
 {
-       u64 now = get_timestamp();
+       u64 now = get_wim_timestamp();
        dentry->creation_time    = now;
        dentry->last_access_time = now;
        dentry->last_write_time  = now;
 }
 
+/* Returns the alternate data stream entry belonging to @dentry that has the
+ * stream name @stream_name. */
 struct ads_entry *dentry_get_ads_entry(struct dentry *dentry,
                                       const char *stream_name)
 {
-       size_t stream_name_len = strlen(stream_name);
+       size_t stream_name_len;
        if (!stream_name)
                return NULL;
-       for (u16 i = 0; i < dentry->num_ads; i++)
-               if (ads_entry_has_name(&dentry->ads_entries[i],
-                                      stream_name, stream_name_len))
-                       return &dentry->ads_entries[i];
+       if (dentry->num_ads) {
+               u16 i = 0;
+               stream_name_len = strlen(stream_name);
+               do {
+                       if (ads_entry_has_name(&dentry->ads_entries[i],
+                                              stream_name, stream_name_len))
+                               return &dentry->ads_entries[i];
+               } while (++i != dentry->num_ads);
+       }
        return NULL;
 }
 
@@ -110,14 +157,19 @@ static void ads_entry_init(struct ads_entry *ads_entry)
        ads_entry->lte_group_list.type = STREAM_TYPE_ADS;
 }
 
-/* Add an alternate stream entry to a dentry and return a pointer to it, or NULL
- * on failure. */
+/* 
+ * Add an alternate stream entry to a dentry and return a pointer to it, or NULL
+ * if memory could not be allocated.
+ */
 struct ads_entry *dentry_add_ads(struct dentry *dentry, const char *stream_name)
 {
        u16 num_ads;
        struct ads_entry *ads_entries;
        struct ads_entry *new_entry;
 
+       DEBUG("Add alternate data stream %s:%s",
+              dentry->file_name_utf8, stream_name);
+
        if (dentry->num_ads == 0xffff)
                return NULL;
        num_ads = dentry->num_ads + 1;
@@ -133,16 +185,24 @@ struct ads_entry *dentry_add_ads(struct dentry *dentry, const char *stream_name)
                        cur->next->prev = cur;
                }
        }
-       dentry->ads_entries = ads_entries;
 
        new_entry = &ads_entries[num_ads - 1];
+       ads_entry_init(new_entry);
        if (change_ads_name(new_entry, stream_name) != 0)
                return NULL;
+       dentry->ads_entries = ads_entries;
        dentry->num_ads = num_ads;
-       ads_entry_init(new_entry);
        return new_entry;
 }
 
+/* Remove an alternate data stream from a dentry.
+ *
+ * The corresponding lookup table entry for the stream is NOT changed.
+ *
+ * @dentry:    The dentry
+ * @ads_entry: The alternate data stream entry (it MUST be one of the
+ *                ads_entry's in the array dentry->ads_entries).
+ */
 void dentry_remove_ads(struct dentry *dentry, struct ads_entry *ads_entry)
 {
        u16 idx;
@@ -282,12 +342,12 @@ void calculate_subdir_offsets(struct dentry *dentry, u64 *subdir_offset_p)
 
        child = dentry->children;
        dentry->subdir_offset = *subdir_offset_p;
-       if (child) {
 
+       if (child) {
                /* Advance the subdir offset by the amount of space the children
                 * of this dentry take up. */
                do {
-                       *subdir_offset_p += dentry_total_length(child);
+                       *subdir_offset_p += dentry_correct_total_length(child);
                        child = child->next;
                } while (child != dentry->children);
 
@@ -303,7 +363,7 @@ void calculate_subdir_offsets(struct dentry *dentry, u64 *subdir_offset_p)
        } else {
                /* On disk, childless directories have a valid subdir_offset
                 * that points to an 8-byte end-of-directory dentry.  Regular
-                * files have a subdir_offset of 0. */
+                * files or reparse points have a subdir_offset of 0. */
                if (dentry_is_directory(dentry))
                        *subdir_offset_p += 8;
                else
@@ -315,7 +375,7 @@ void calculate_subdir_offsets(struct dentry *dentry, u64 *subdir_offset_p)
 /* Returns the child of @dentry that has the file name @name.  
  * Returns NULL if no child has the name. */
 struct dentry *get_dentry_child_with_name(const struct dentry *dentry, 
-                                                       const char *name)
+                                         const char *name)
 {
        struct dentry *child;
        size_t name_len;
@@ -334,7 +394,8 @@ struct dentry *get_dentry_child_with_name(const struct dentry *dentry,
 
 /* Retrieves the dentry that has the UTF-8 @path relative to the dentry
  * @cur_dir.  Returns NULL if no dentry having the path is found. */
-static struct dentry *get_dentry_relative_path(struct dentry *cur_dir, const char *path)
+static struct dentry *get_dentry_relative_path(struct dentry *cur_dir,
+                                              const char *path)
 {
        struct dentry *child;
        size_t base_len;
@@ -365,7 +426,8 @@ struct dentry *get_dentry(WIMStruct *w, const char *path)
        return get_dentry_relative_path(root, path);
 }
 
-/* Returns the parent directory for the @path. */
+/* Returns the dentry that corresponds to the parent directory of @path, or NULL
+ * if the dentry is not found. */
 struct dentry *get_parent_dentry(WIMStruct *w, const char *path)
 {
        size_t path_len = strlen(path);
@@ -386,52 +448,79 @@ int print_dentry_full_path(struct dentry *dentry, void *ignore)
        return 0;
 }
 
+/* We want to be able to show the names of the file attribute flags that are
+ * set. */
 struct file_attr_flag {
        u32 flag;
        const char *name;
 };
 struct file_attr_flag file_attr_flags[] = {
-       {FILE_ATTRIBUTE_READONLY,               "READONLY"},
-       {FILE_ATTRIBUTE_HIDDEN,         "HIDDEN"},
-       {FILE_ATTRIBUTE_SYSTEM,         "SYSTEM"},
-       {FILE_ATTRIBUTE_DIRECTORY,              "DIRECTORY"},
-       {FILE_ATTRIBUTE_ARCHIVE,                "ARCHIVE"},
-       {FILE_ATTRIBUTE_DEVICE,         "DEVICE"},
-       {FILE_ATTRIBUTE_NORMAL,         "NORMAL"},
-       {FILE_ATTRIBUTE_TEMPORARY,              "TEMPORARY"},
-       {FILE_ATTRIBUTE_SPARSE_FILE,    "SPARSE_FILE"},
-       {FILE_ATTRIBUTE_REPARSE_POINT,  "REPARSE_POINT"},
-       {FILE_ATTRIBUTE_COMPRESSED,             "COMPRESSED"},
-       {FILE_ATTRIBUTE_OFFLINE,                "OFFLINE"},
+       {FILE_ATTRIBUTE_READONLY,           "READONLY"},
+       {FILE_ATTRIBUTE_HIDDEN,             "HIDDEN"},
+       {FILE_ATTRIBUTE_SYSTEM,             "SYSTEM"},
+       {FILE_ATTRIBUTE_DIRECTORY,          "DIRECTORY"},
+       {FILE_ATTRIBUTE_ARCHIVE,            "ARCHIVE"},
+       {FILE_ATTRIBUTE_DEVICE,             "DEVICE"},
+       {FILE_ATTRIBUTE_NORMAL,             "NORMAL"},
+       {FILE_ATTRIBUTE_TEMPORARY,          "TEMPORARY"},
+       {FILE_ATTRIBUTE_SPARSE_FILE,        "SPARSE_FILE"},
+       {FILE_ATTRIBUTE_REPARSE_POINT,      "REPARSE_POINT"},
+       {FILE_ATTRIBUTE_COMPRESSED,         "COMPRESSED"},
+       {FILE_ATTRIBUTE_OFFLINE,            "OFFLINE"},
        {FILE_ATTRIBUTE_NOT_CONTENT_INDEXED,"NOT_CONTENT_INDEXED"},
-       {FILE_ATTRIBUTE_ENCRYPTED,              "ENCRYPTED"},
-       {FILE_ATTRIBUTE_VIRTUAL,                "VIRTUAL"},
+       {FILE_ATTRIBUTE_ENCRYPTED,          "ENCRYPTED"},
+       {FILE_ATTRIBUTE_VIRTUAL,            "VIRTUAL"},
 };
 
-/* Prints a directory entry.  @lookup_table is a pointer to the lookup table, or
- * NULL if the resource entry for the dentry is not to be printed. */
+/* Prints a directory entry.  @lookup_table is a pointer to the lookup table, if
+ * available.  If the dentry is unresolved and the lookup table is NULL, the
+ * lookup table entries will not be printed.  Otherwise, they will be. */
 int print_dentry(struct dentry *dentry, void *lookup_table)
 {
+       const u8 *hash;
        struct lookup_table_entry *lte;
-       unsigned i;
+       time_t time;
+       char *p;
 
        printf("[DENTRY]\n");
        printf("Length            = %"PRIu64"\n", dentry->length);
        printf("Attributes        = 0x%x\n", dentry->attributes);
-       for (i = 0; i < ARRAY_LEN(file_attr_flags); i++)
+       for (unsigned i = 0; i < ARRAY_LEN(file_attr_flags); i++)
                if (file_attr_flags[i].flag & dentry->attributes)
                        printf("    FILE_ATTRIBUTE_%s is set\n",
                                file_attr_flags[i].name);
        printf("Security ID       = %d\n", dentry->security_id);
        printf("Subdir offset     = %"PRIu64"\n", dentry->subdir_offset);
-       /*printf("Unused1           = 0x%"PRIu64"\n", dentry->unused1);*/
-       /*printf("Unused2           = %"PRIu64"\n", dentry->unused2);*/
-       printf("Creation Time     = 0x%"PRIx64"\n", dentry->creation_time);
-       printf("Last Access Time  = 0x%"PRIx64"\n", dentry->last_access_time);
-       printf("Last Write Time   = 0x%"PRIx64"\n", dentry->last_write_time);
-       printf("Hash              = 0x"); 
-       print_hash(dentry->hash); 
-       putchar('\n');
+#if 0
+       printf("Unused1           = 0x%"PRIu64"\n", dentry->unused1);
+       printf("Unused2           = %"PRIu64"\n", dentry->unused2);
+#endif
+#if 0
+       printf("Creation Time     = 0x%"PRIx64"\n");
+       printf("Last Access Time  = 0x%"PRIx64"\n");
+       printf("Last Write Time   = 0x%"PRIx64"\n");
+#endif
+
+       /* Translate the timestamps into something readable */
+       time_t creat_time = wim_timestamp_to_unix(dentry->creation_time);
+       time_t access_time = wim_timestamp_to_unix(dentry->last_access_time);
+       time_t mod_time = wim_timestamp_to_unix(dentry->last_write_time);
+
+       time = wim_timestamp_to_unix(dentry->creation_time);
+       p = asctime(gmtime(&time));
+       *(strrchr(p, '\n')) = '\0';
+       printf("Creation Time     = %s UTC\n", p);
+
+       time = wim_timestamp_to_unix(dentry->last_access_time);
+       p = asctime(gmtime(&time));
+       *(strrchr(p, '\n')) = '\0';
+       printf("Last Access Time  = %s UTC\n", p);
+
+       time = wim_timestamp_to_unix(dentry->last_write_time);
+       p = asctime(gmtime(&time));
+       *(strrchr(p, '\n')) = '\0';
+       printf("Last Write Time   = %s UTC\n", p);
+
        printf("Reparse Tag       = 0x%"PRIx32"\n", dentry->reparse_tag);
        printf("Hard Link Group   = 0x%"PRIx64"\n", dentry->hard_link);
        printf("Number of Alternate Data Streams = %hu\n", dentry->num_ads);
@@ -446,30 +535,37 @@ int print_dentry(struct dentry *dentry, void *lookup_table)
        puts("\"");
        printf("Short Name Length = %hu\n", dentry->short_name_len);
        printf("Full Path (UTF-8) = \"%s\"\n", dentry->full_path_utf8);
-       if (lookup_table && (lte = __lookup_resource(lookup_table, dentry->hash)))
-               print_lookup_table_entry(lte, NULL);
-       else
-               putchar('\n');
+       lte = dentry_stream_lte(dentry, 0, lookup_table);
+       if (lte) {
+               print_lookup_table_entry(lte);
+       } else {
+               hash = dentry_stream_hash(dentry, 0);
+               if (hash) {
+                       printf("Hash              = 0x"); 
+                       print_hash(hash);
+                       putchar('\n');
+                       putchar('\n');
+               }
+       }
        for (u16 i = 0; i < dentry->num_ads; i++) {
                printf("[Alternate Stream Entry %u]\n", i);
                printf("Name = \"%s\"\n", dentry->ads_entries[i].stream_name_utf8);
                printf("Name Length (UTF-16) = %u\n",
                                dentry->ads_entries[i].stream_name_len);
-               printf("Hash              = 0x"); 
-               print_hash(dentry->ads_entries[i].hash); 
-               if (lookup_table &&
-                    (lte = __lookup_resource(lookup_table,
-                                             dentry->ads_entries[i].hash)))
-               {
-                       print_lookup_table_entry(lte, NULL);
-               } else {
+               hash = dentry_stream_hash(dentry, i + 1);
+               if (hash) {
+                       printf("Hash              = 0x"); 
+                       print_hash(hash);
                        putchar('\n');
                }
+               print_lookup_table_entry(dentry_stream_lte(dentry, i + 1,
+                                                          lookup_table));
        }
        return 0;
 }
 
-static inline void dentry_common_init(struct dentry *dentry)
+/* Initializations done on every `struct dentry'. */
+static void dentry_common_init(struct dentry *dentry)
 {
        memset(dentry, 0, sizeof(struct dentry));
        dentry->refcnt = 1;
@@ -481,8 +577,9 @@ static inline void dentry_common_init(struct dentry *dentry)
 /* 
  * Creates an unlinked directory entry.
  *
- * @name:    The base name of the new dentry.
- * @return:  A pointer to the new dentry, or NULL if out of memory.
+ * @name:  The UTF-8 filename of the new dentry.
+ *
+ * Returns a pointer to the new dentry, or NULL if out of memory.
  */
 struct dentry *new_dentry(const char *name)
 {
@@ -526,10 +623,13 @@ static void __destroy_dentry(struct dentry *dentry)
        FREE(dentry->extracted_file);
 }
 
+/* Frees a WIM dentry. */
 void free_dentry(struct dentry *dentry)
 {
        wimlib_assert(dentry);
        __destroy_dentry(dentry);
+       /* Don't destroy the ADS entries if they "belong" to a different dentry
+        * */
        if (dentry->ads_entries_status != ADS_ENTRIES_USER)
                dentry_free_ads_entries(dentry);
        FREE(dentry);
@@ -557,12 +657,13 @@ void put_dentry(struct dentry *dentry)
 }
 
 
-/* clones a dentry.
+/* Partically clones a dentry.
  *
  * Beware:
- *     - memory for file names is not cloned
+ *     - memory for file names is not cloned (the pointers are all set to NULL
+ *       and the lengths are set to zero)
  *     - next, prev, and children pointers and not touched
- *     - stream entries are not cloned.
+ *     - stream entries are not cloned (pointer left untouched).
  */
 struct dentry *clone_dentry(struct dentry *old)
 {
@@ -579,24 +680,21 @@ struct dentry *clone_dentry(struct dentry *old)
        return new;
 }
 
-/* Arguments for do_free_dentry(). */
-struct free_dentry_args {
-       struct lookup_table *lookup_table;
-       bool lt_decrement_refcnt;
-};
-
 /* 
  * This function is passed as an argument to for_dentry_in_tree_depth() in order
  * to free a directory tree.  __args is a pointer to a `struct free_dentry_args'.
  */
-static int do_free_dentry(struct dentry *dentry, void *__args)
+static int do_free_dentry(struct dentry *dentry, void *__lookup_table)
 {
-       struct free_dentry_args *args = (struct free_dentry_args*)__args;
+       struct lookup_table *lookup_table = __lookup_table;
+       struct lookup_table_entry *lte;
+       unsigned i;
 
-       if (args->lt_decrement_refcnt && !dentry_is_directory(dentry)) {
-               wimlib_assert(!dentry->resolved);
-               lookup_table_decrement_refcnt(args->lookup_table, 
-                                             dentry->hash);
+       if (lookup_table) {
+               for (i = 0; i <= dentry->num_ads; i++) {
+                       lte = dentry_stream_lte(dentry, i, lookup_table);
+                       lte_decrement_refcnt(lte, lookup_table);
+               }
        }
 
        wimlib_assert(dentry->refcnt != 0);
@@ -609,20 +707,16 @@ static int do_free_dentry(struct dentry *dentry, void *__args)
  * Unlinks and frees a dentry tree.
  *
  * @root:              The root of the tree.
- * @lookup_table:      The lookup table for dentries.
- * @decrement_refcnt:          True if the dentries in the tree are to have their 
- *                     reference counts in the lookup table decremented.
+ * @lookup_table:      The lookup table for dentries.  If non-NULL, the
+ *                     reference counts in the lookup table for the lookup
+ *                     table entries corresponding to the dentries will be
+ *                     decremented.
  */
-void free_dentry_tree(struct dentry *root, struct lookup_table *lookup_table, 
-                     bool lt_decrement_refcnt)
+void free_dentry_tree(struct dentry *root, struct lookup_table *lookup_table)
 {
        if (!root || !root->parent)
                return;
-
-       struct free_dentry_args args;
-       args.lookup_table        = lookup_table;
-       args.lt_decrement_refcnt = lt_decrement_refcnt;
-       for_dentry_in_tree_depth(root, do_free_dentry, &args);
+       for_dentry_in_tree_depth(root, do_free_dentry, lookup_table);
 }
 
 int increment_dentry_refcnt(struct dentry *dentry, void *ignore)
@@ -676,17 +770,6 @@ void unlink_dentry(struct dentry *dentry)
        }
 }
 
-
-/* Recalculates the length of @dentry based on its file name length and short
- * name length.  */
-static inline void recalculate_dentry_size(struct dentry *dentry)
-{
-       dentry->length = WIM_DENTRY_DISK_SIZE + dentry->file_name_len + 
-                        2 + dentry->short_name_len;
-       /* Must be multiple of 8. */
-       dentry->length = (dentry->length + 7) & ~7;
-}
-
 /* Duplicates a UTF-8 name into UTF-8 and UTF-16 strings and returns the strings
  * and their lengths in the pointer arguments */
 int get_names(char **name_utf16_ret, char **name_utf8_ret,
@@ -730,16 +813,18 @@ int change_dentry_name(struct dentry *dentry, const char *new_name)
                        &dentry->file_name_len, &dentry->file_name_utf8_len,
                         new_name);
        if (ret == 0)
-               recalculate_dentry_size(dentry);
+               dentry->length = dentry_correct_length(dentry);
        return ret;
 }
 
+/*
+ * Changes the name of an alternate data stream */
 int change_ads_name(struct ads_entry *entry, const char *new_name)
 {
        return get_names(&entry->stream_name, &entry->stream_name_utf8,
                         &entry->stream_name_len,
                         &entry->stream_name_utf8_len,
-                         new_name);
+                        new_name);
 }
 
 /* Parameters for calculate_dentry_statistics(). */
@@ -755,7 +840,6 @@ static int calculate_dentry_statistics(struct dentry *dentry, void *arg)
 {
        struct image_statistics *stats;
        struct lookup_table_entry *lte; 
-       u16 i;
        
        stats = arg;
 
@@ -764,28 +848,18 @@ static int calculate_dentry_statistics(struct dentry *dentry, void *arg)
        else
                ++*stats->file_count;
 
-       if (dentry->resolved)
-               lte = dentry->lte;
-       else
-               lte = __lookup_resource(stats->lookup_table, dentry->hash);
-       i = 0;
-       while (1) {
+       for (unsigned i = 0; i <= dentry->num_ads; i++) {
+               lte = dentry_stream_lte(dentry, i, stats->lookup_table);
                if (lte) {
-                       u64 size = lte->resource_entry.original_size;
-                       *stats->total_bytes += size;
+                       *stats->total_bytes += wim_resource_size(lte);
                        if (++lte->out_refcnt == 1)
-                               *stats->hard_link_bytes += size;
+                               *stats->hard_link_bytes += wim_resource_size(lte);
                }
-               if (i == dentry->num_ads)
-                       break;
-               lte = __lookup_resource(stats->lookup_table,
-                                       dentry->ads_entries[i].hash);
-               i++;
        }
-
        return 0;
 }
 
+/* Calculates some statistics about a dentry tree. */
 void calculate_dir_tree_statistics(struct dentry *root, struct lookup_table *table, 
                                   u64 *dir_count_ret, u64 *file_count_ret, 
                                   u64 *total_bytes_ret, 
@@ -805,25 +879,70 @@ void calculate_dir_tree_statistics(struct dentry *root, struct lookup_table *tab
        for_dentry_in_tree(root, calculate_dentry_statistics, &stats);
 }
 
+
+/* 
+ * Reads the alternate data stream entries for a dentry.
+ *
+ * @p: Pointer to buffer that starts with the first alternate stream entry.
+ *
+ * @dentry:    Dentry to load the alternate data streams into.
+ *                     @dentry->num_ads must have been set to the number of
+ *                     alternate data streams that are expected.
+ *
+ * @remaining_size:    Number of bytes of data remaining in the buffer pointed
+ *                             to by @p.
+ *
+ * The format of the on-disk alternate stream entries is as follows:
+ *
+ * struct ads_entry_on_disk {
+ *     u64  length;          // Length of the entry, in bytes.  This includes
+ *                                 all fields (including the stream name and 
+ *                                 null terminator if present, AND the padding!).
+ *     u64  reserved;        // Seems to be unused
+ *     u8   hash[20];        // SHA1 message digest of the uncompressed stream
+ *     u16  stream_name_len; // Length of the stream name, in bytes
+ *     char stream_name[];   // Stream name in UTF-16LE, @stream_name_len bytes long,
+ *                                  not including null terminator
+ *     u16  zero;            // UTF-16 null terminator for the stream name, NOT
+ *                                 included in @stream_name_len.  Based on what
+ *                                 I've observed from filenames in dentries,
+ *                                 this field should not exist when
+ *                                 (@stream_name_len == 0), but you can't
+ *                                 actually tell because of the padding anyway
+ *                                 (provided that the padding is zeroed, which
+ *                                 it always seems to be).
+ *     char padding[];       // Padding to make the size a multiple of 8 bytes.
+ * };
+ *
+ * In addition, the entries are 8-byte aligned.
+ *
+ * Return 0 on success or nonzero on failure.  On success, dentry->ads_entries
+ * is set to an array of `struct ads_entry's of length dentry->num_ads.  On
+ * failure, @dentry is not modified.
+ */
 static int read_ads_entries(const u8 *p, struct dentry *dentry,
                            u64 remaining_size)
 {
-       u16 num_ads = dentry->num_ads;
-       struct ads_entry *ads_entries = CALLOC(num_ads, sizeof(struct ads_entry));
+       u16 num_ads;
+       struct ads_entry *ads_entries;
        int ret;
+
+       num_ads = dentry->num_ads;
+       ads_entries = CALLOC(num_ads, sizeof(struct ads_entry));
        if (!ads_entries) {
                ERROR("Could not allocate memory for %"PRIu16" "
                      "alternate data stream entries", num_ads);
                return WIMLIB_ERR_NOMEM;
        }
-       DEBUG2("Reading %"PRIu16" alternate data streams "
-              "(remaining size = %"PRIu64")", num_ads, remaining_size);
 
        for (u16 i = 0; i < num_ads; i++) {
                struct ads_entry *cur_entry = &ads_entries[i];
                u64 length;
+               u64 length_no_padding;
+               u64 total_length;
                size_t utf8_len;
                const char *p_save = p;
+
                /* Read the base stream entry, excluding the stream name. */
                if (remaining_size < WIM_ADS_ENTRY_DISK_SIZE) {
                        ERROR("Stream entries go past end of metadata resource");
@@ -831,48 +950,81 @@ static int read_ads_entries(const u8 *p, struct dentry *dentry,
                        ret = WIMLIB_ERR_INVALID_DENTRY;
                        goto out_free_ads_entries;
                }
-               remaining_size -= WIM_ADS_ENTRY_DISK_SIZE;
-
-               p = get_u64(p, &length); /* ADS entry length */
-
-               DEBUG2("ADS length = %"PRIu64, length);
 
-               p += 8; /* Unused */
-               p = get_bytes(p, WIM_HASH_SIZE, (u8*)cur_entry->hash);
+               p = get_u64(p, &length);
+               p += 8; /* Skip the reserved field */
+               p = get_bytes(p, SHA1_HASH_SIZE, (u8*)cur_entry->hash);
                p = get_u16(p, &cur_entry->stream_name_len);
 
-               DEBUG2("Stream name length = %u", cur_entry->stream_name_len);
-
                cur_entry->stream_name = NULL;
                cur_entry->stream_name_utf8 = NULL;
 
-               if (remaining_size < cur_entry->stream_name_len + 2) {
+               /* Length including neither the null terminator nor the padding
+                * */
+               length_no_padding = WIM_ADS_ENTRY_DISK_SIZE +
+                                   cur_entry->stream_name_len;
+
+               /* Length including the null terminator and the padding */
+               total_length = ((length_no_padding + 2) + 7) & ~7;
+
+               wimlib_assert(total_length == ads_entry_total_length(cur_entry));
+
+               if (remaining_size < length_no_padding) {
                        ERROR("Stream entries go past end of metadata resource");
-                       ERROR("(remaining_size = %"PRIu64" bytes, stream_name_len "
-                             "= %"PRIu16" bytes", remaining_size,
-                             cur_entry->stream_name_len);
+                       ERROR("(remaining_size = %"PRIu64" bytes, "
+                             "length_no_padding = %"PRIu16" bytes)",
+                             remaining_size, length_no_padding);
                        ret = WIMLIB_ERR_INVALID_DENTRY;
                        goto out_free_ads_entries;
                }
-               remaining_size -= cur_entry->stream_name_len + 2;
 
-               cur_entry->stream_name = MALLOC(cur_entry->stream_name_len);
-               if (!cur_entry->stream_name) {
-                       ret = WIMLIB_ERR_NOMEM;
+               /* The @length field in the on-disk ADS entry is expected to be
+                * equal to @total_length, which includes all of the entry and
+                * the padding that follows it to align the next ADS entry to an
+                * 8-byte boundary.  However, to be safe, we'll accept the
+                * length field as long as it's not less than the un-padded
+                * total length and not more than the padded total length. */
+               if (length < length_no_padding || length > total_length) {
+                       ERROR("Stream entry has unexpected length "
+                             "field (length field = %"PRIu64", "
+                             "unpadded total length = %"PRIu64", "
+                             "padded total length = %"PRIu64")",
+                             length, length_no_padding, total_length);
+                       ret = WIMLIB_ERR_INVALID_DENTRY;
                        goto out_free_ads_entries;
                }
-               get_bytes(p, cur_entry->stream_name_len,
-                         (u8*)cur_entry->stream_name);
-               cur_entry->stream_name_utf8 = utf16_to_utf8(cur_entry->stream_name,
-                                                           cur_entry->stream_name_len,
-                                                           &utf8_len);
-               cur_entry->stream_name_utf8_len = utf8_len;
-
-               if (!cur_entry->stream_name_utf8) {
-                       ret = WIMLIB_ERR_NOMEM;
-                       goto out_free_ads_entries;
+
+               if (cur_entry->stream_name_len) {
+                       cur_entry->stream_name = MALLOC(cur_entry->stream_name_len);
+                       if (!cur_entry->stream_name) {
+                               ret = WIMLIB_ERR_NOMEM;
+                               goto out_free_ads_entries;
+                       }
+                       get_bytes(p, cur_entry->stream_name_len,
+                                 (u8*)cur_entry->stream_name);
+                       cur_entry->stream_name_utf8 = utf16_to_utf8(cur_entry->stream_name,
+                                                                   cur_entry->stream_name_len,
+                                                                   &utf8_len);
+                       cur_entry->stream_name_utf8_len = utf8_len;
+
+                       if (!cur_entry->stream_name_utf8) {
+                               ret = WIMLIB_ERR_NOMEM;
+                               goto out_free_ads_entries;
+                       }
                }
-               p = p_save + ads_entry_length(cur_entry);
+               /* It's expected that the size of every ADS entry is a multiple
+                * of 8.  However, to be safe, I'm allowing the possibility of
+                * an ADS entry at the very end of the metadata resource ending
+                * un-aligned.  So although we still need to increment the input
+                * pointer by @total_length to reach the next ADS entry, it's
+                * possible that less than @total_length is actually remaining
+                * in the metadata resource. We should set the remaining size to
+                * 0 bytes if this happens. */
+               p = p_save + total_length;
+               if (remaining_size < total_length)
+                       remaining_size = 0;
+               else
+                       remaining_size -= total_length;
        }
        dentry->ads_entries = ads_entries;
        return 0;
@@ -886,16 +1038,28 @@ out_free_ads_entries:
 }
 
 /* 
- * Reads a directory entry from the metadata resource.
+ * Reads a directory entry, including all alternate data stream entries that
+ * follow it, from the WIM image's metadata resource.
+ *
+ * @metadata_resource: Buffer containing the uncompressed metadata resource.
+ * @metadata_resource_len:   Length of the metadata resource.
+ * @offset:    Offset of this directory entry in the metadata resource.
+ * @dentry:    A `struct dentry' that will be filled in by this function.
+ *
+ * Return 0 on success or nonzero on failure.  On failure, @dentry have been
+ * modified, bu it will be left with no pointers to any allocated buffers.
+ * On success, the dentry->length field must be examined.  If zero, this was a
+ * special "end of directory" dentry and not a real dentry.  If nonzero, this
+ * was a real dentry.
  */
 int read_dentry(const u8 metadata_resource[], u64 metadata_resource_len, 
                u64 offset, struct dentry *dentry)
 {
        const u8 *p;
        u64 calculated_size;
-       char *file_name;
-       char *file_name_utf8;
-       char *short_name;
+       char *file_name = NULL;
+       char *file_name_utf8 = NULL;
+       char *short_name = NULL;
        u16 short_name_len;
        u16 file_name_len;
        size_t file_name_utf8_len;
@@ -904,15 +1068,15 @@ int read_dentry(const u8 metadata_resource[], u64 metadata_resource_len,
        dentry_common_init(dentry);
 
        /*Make sure the dentry really fits into the metadata resource.*/
-       if (offset + 8 > metadata_resource_len) {
+       if (offset + 8 > metadata_resource_len || offset + 8 < offset) {
                ERROR("Directory entry starting at %"PRIu64" ends past the "
                      "end of the metadata resource (size %"PRIu64")",
                      offset, metadata_resource_len);
                return WIMLIB_ERR_INVALID_DENTRY;
        }
 
-       /* Before reading the whole entry, we need to read just the length.
-        * This is because aentry of length 8 (that is, just the length field)
+       /* Before reading the whole dentry, we need to read just the length.
+        * This is because a dentry of length 8 (that is, just the length field)
         * terminates the list of sibling directory entries. */
 
        p = get_u64(&metadata_resource[offset], &dentry->length);
@@ -920,11 +1084,17 @@ int read_dentry(const u8 metadata_resource[], u64 metadata_resource_len,
        /* A zero length field (really a length of 8, since that's how big the
         * directory entry is...) indicates that this is the end of directory
         * dentry.  We do not read it into memory as an actual dentry, so just
-        * return true in that case. */
+        * return successfully in that case. */
        if (dentry->length == 0)
                return 0;
 
-       if (offset + dentry->length >= metadata_resource_len) {
+       /* If the dentry does not overflow the metadata resource buffer and is
+        * not too short, read the rest of it (excluding the alternate data
+        * streams, but including the file name and short name variable-length
+        * fields) into memory. */
+       if (offset + dentry->length >= metadata_resource_len
+           || offset + dentry->length < offset)
+       {
                ERROR("Directory entry at offset %"PRIu64" and with size "
                      "%"PRIu64" ends past the end of the metadata resource "
                      "(size %"PRIu64")",
@@ -932,9 +1102,6 @@ int read_dentry(const u8 metadata_resource[], u64 metadata_resource_len,
                return WIMLIB_ERR_INVALID_DENTRY;
        }
 
-       /* If it is a recognized length, read the rest of the directory entry.
-        * Note: The root directory entry has no name, and its length does not
-        * include the short name length field.  */
        if (dentry->length < WIM_DENTRY_DISK_SIZE) {
                ERROR("Directory entry has invalid length of %"PRIu64" bytes",
                      dentry->length);
@@ -954,7 +1121,7 @@ int read_dentry(const u8 metadata_resource[], u64 metadata_resource_len,
        p = get_u64(p, &dentry->last_access_time);
        p = get_u64(p, &dentry->last_write_time);
 
-       p = get_bytes(p, WIM_HASH_SIZE, dentry->hash);
+       p = get_bytes(p, SHA1_HASH_SIZE, dentry->hash);
        
        /*
         * I don't know what's going on here.  It seems like M$ screwed up the
@@ -974,95 +1141,117 @@ int read_dentry(const u8 metadata_resource[], u64 metadata_resource_len,
 
        /* By the way, the reparse_reserved field does not actually exist (at
         * least when the file is not a reparse point) */
-
        
        p = get_u16(p, &dentry->num_ads);
 
        p = get_u16(p, &short_name_len);
        p = get_u16(p, &file_name_len);
 
-       calculated_size = WIM_DENTRY_DISK_SIZE + file_name_len + 2 +
-                         short_name_len;
+       /* We now know the length of the file name and short name.  Make sure
+        * the length of the dentry is large enough to actually hold them. 
+        *
+        * The calculated length here is unaligned to allow for the possibility
+        * that the dentry->length names an unaligned length, although this
+        * would be unexpected. */
+       calculated_size = __dentry_correct_length_unaligned(file_name_len,
+                                                           short_name_len);
 
        if (dentry->length < calculated_size) {
                ERROR("Unexpected end of directory entry! (Expected "
-                     "%"PRIu64" bytes, got %"PRIu64" bytes. "
+                     "at least %"PRIu64" bytes, got %"PRIu64" bytes. "
                      "short_name_len = %hu, file_name_len = %hu)", 
                      calculated_size, dentry->length,
                      short_name_len, file_name_len);
                return WIMLIB_ERR_INVALID_DENTRY;
        }
 
-       /* Read the filename. */
-       file_name = MALLOC(file_name_len);
-       if (!file_name) {
-               ERROR("Failed to allocate %hu bytes for dentry file name",
-                     file_name_len);
-               return WIMLIB_ERR_NOMEM;
-       }
-       p = get_bytes(p, file_name_len, file_name);
+       /* Read the filename if present.  Note: if the filename is empty, there
+        * is no null terminator following it. */
+       if (file_name_len) {
+               file_name = MALLOC(file_name_len);
+               if (!file_name) {
+                       ERROR("Failed to allocate %hu bytes for dentry file name",
+                             file_name_len);
+                       return WIMLIB_ERR_NOMEM;
+               }
+               p = get_bytes(p, file_name_len, file_name);
 
-       /* Convert filename to UTF-8. */
-       file_name_utf8 = utf16_to_utf8(file_name, file_name_len, 
-                                      &file_name_utf8_len);
+               /* Convert filename to UTF-8. */
+               file_name_utf8 = utf16_to_utf8(file_name, file_name_len, 
+                                              &file_name_utf8_len);
 
-       if (!file_name_utf8) {
-               ERROR("Failed to allocate memory to convert UTF-16 "
-                     "filename (%hu bytes) to UTF-8", file_name_len);
-               ret = WIMLIB_ERR_NOMEM;
-               goto out_free_file_name;
+               if (!file_name_utf8) {
+                       ERROR("Failed to allocate memory to convert UTF-16 "
+                             "filename (%hu bytes) to UTF-8", file_name_len);
+                       ret = WIMLIB_ERR_NOMEM;
+                       goto out_free_file_name;
+               }
+               if (*(u16*)p)
+                       WARNING("Expected two zero bytes following the file name "
+                               "`%s', but found non-zero bytes", file_name_utf8);
+               p += 2;
        }
 
-       /* Undocumented padding between file name and short name.  This probably
-        * is supposed to be a terminating null character. */
-       p += 2;
-
-       /* Read the short filename. */
-       short_name = MALLOC(short_name_len);
-       if (!short_name) {
-               ERROR("Failed to allocate %hu bytes for short filename",
-                     short_name_len);
-               ret = WIMLIB_ERR_NOMEM;
-               goto out_free_file_name_utf8;
+       /* Align the calculated size */
+       calculated_size = (calculated_size + 7) & ~7;
+
+       if (dentry->length > calculated_size) {
+               /* Weird; the dentry says it's longer than it should be.  Note
+                * that the length field does NOT include the size of the
+                * alternate stream entries. */
+
+               /* Strangely, some directory entries inexplicably have a little
+                * over 70 bytes of extra data.  The exact amount of data seems
+                * to be 72 bytes, but it is aligned on the next 8-byte
+                * boundary.  It does NOT seem to be alternate data stream
+                * entries.  Here's an example of the aligned data:
+                *
+                * 01000000 40000000 6c786bba c58ede11 b0bb0026 1870892a b6adb76f
+                * e63a3e46 8fca8653 0d2effa1 6c786bba c58ede11 b0bb0026 1870892a
+                * 00000000 00000000 00000000 00000000
+                *
+                * Here's one interpretation of how the data is laid out.
+                *
+                * struct unknown {
+                *      u32 field1; (always 0x00000001)
+                *      u32 field2; (always 0x40000000)
+                *      u8  data[48]; (???)
+                *      u64 reserved1; (always 0)
+                *      u64 reserved2; (always 0)
+                * };*/
+               WARNING("Dentry for file or directory `%s' has %zu extra "
+                       "bytes of data",
+                       file_name_utf8, dentry->length - calculated_size);
        }
 
-       p = get_bytes(p, short_name_len, short_name);
+       /* Read the short filename if present.  Note: if there is no short
+        * filename, there is no null terminator following it. */
+       if (short_name_len) {
+               short_name = MALLOC(short_name_len);
+               if (!short_name) {
+                       ERROR("Failed to allocate %hu bytes for short filename",
+                             short_name_len);
+                       ret = WIMLIB_ERR_NOMEM;
+                       goto out_free_file_name_utf8;
+               }
 
-       /* Some directory entries inexplicibly have a little over 70 bytes of
-        * extra data.  The exact amount of data seems to be 72 bytes, but it is
-        * aligned on the next 8-byte boundary.  Here's an example of the
-        * aligned data:
-        *
-        * 01000000400000006c786bbac58ede11b0bb00261870892ab6adb76fe63a3
-        * e468fca86530d2effa16c786bbac58ede11b0bb00261870892a0000000000
-        * 0000000000000000000000
-        *
-        * Here's one interpretation of how the data is laid out.
-        *
-        * struct unknown {
-        *      u32 field1; (always 0x00000001)
-        *      u32 field2; (always 0x40000000)
-        *      u16 field3;
-        *      u32 field4;
-        *      u32 field5;
-        *      u32 field6;
-        *      u8  data[48]; (???)
-        *      u64 reserved1; (always 0)
-        *      u64 reserved2; (always 0)
-        * };*/
-#if 0
-       if (dentry->length - calculated_size >= WIM_ADS_ENTRY_DISK_SIZE) {
-               printf("%s: %lu / %lu (", file_name_utf8, 
-                               calculated_size, dentry->length);
-               print_string(p + WIM_ADS_ENTRY_DISK_SIZE, dentry->length - calculated_size - WIM_ADS_ENTRY_DISK_SIZE);
-               puts(")");
-               print_byte_field(p, dentry->length - calculated_size);
-               putchar('\n');
+               p = get_bytes(p, short_name_len, short_name);
+               if (*(u16*)p)
+                       WARNING("Expected two zero bytes following the file name "
+                               "`%s', but found non-zero bytes", file_name_utf8);
+               p += 2;
        }
-#endif
 
+       /* 
+        * Read the alternate data streams, if present.  dentry->num_ads tells
+        * us how many they are, and they will directly follow the dentry
+        * on-disk.
+        *
+        * Note that each alternate data stream entry begins on an 8-byte
+        * aligned boundary, and the alternate data stream entries are NOT
+        * included in the dentry->length field for some reason.
+        */
        if (dentry->num_ads != 0) {
-               calculated_size = (calculated_size + 7) & ~7;
                if (calculated_size > metadata_resource_len - offset) {
                        ERROR("Not enough space in metadata resource for "
                              "alternate stream entries");
@@ -1076,6 +1265,8 @@ int read_dentry(const u8 metadata_resource[], u64 metadata_resource_len,
                        goto out_free_short_name;
        }
 
+       /* We've read all the data for this dentry.  Set the names and their
+        * lengths, and we've done. */
        dentry->file_name          = file_name;
        dentry->file_name_utf8     = file_name_utf8;
        dentry->short_name         = short_name;
@@ -1092,8 +1283,78 @@ out_free_file_name:
        return ret;
 }
 
+/* Run some miscellaneous verifications on a WIM dentry */
+int verify_dentry(struct dentry *dentry, void *wim)
+{
+       const WIMStruct *w = wim;
+       const struct lookup_table *table = w->lookup_table;
+       const struct wim_security_data *sd = wim_const_security_data(w);
+       int ret = WIMLIB_ERR_INVALID_DENTRY;
+
+       /* Check the security ID */
+       if (dentry->security_id < -1) {
+               ERROR("Dentry `%s' has an invalid security ID (%d)",
+                       dentry->full_path_utf8, dentry->security_id);
+               goto out;
+       }
+       if (dentry->security_id >= sd->num_entries) {
+               ERROR("Dentry `%s' has an invalid security ID (%d) "
+                     "(there are only %u entries in the security table)",
+                       dentry->full_path_utf8, dentry->security_id,
+                       sd->num_entries);
+               goto out;
+       }
+
+       /* Check that lookup table entries for all the resources exist, except
+        * if the SHA1 message digest is all 0's, which indicates there is
+        * intentionally no resource there.  */
+       if (w->hdr.total_parts == 1) {
+               for (unsigned i = 0; i <= dentry->num_ads; i++) {
+                       struct lookup_table_entry *lte;
+                       const u8 *hash;
+                       hash = dentry_stream_hash_unresolved(dentry, i);
+                       lte = __lookup_resource(table, hash);
+                       if (!lte && !is_zero_hash(hash)) {
+                               ERROR("Could not find lookup table entry for stream "
+                                     "%u of dentry `%s'", i, dentry->full_path_utf8);
+                               goto out;
+                       }
+               }
+       }
+
+       /* Make sure there is only one un-named stream. */
+       unsigned num_unnamed_streams = 0;
+       unsigned unnamed_stream_idx;
+       for (unsigned i = 0; i <= dentry->num_ads; i++) {
+               const u8 *hash;
+               hash = dentry_stream_hash_unresolved(dentry, i);
+               if (!dentry_stream_name_len(dentry, i) && !is_zero_hash(hash)) {
+                       num_unnamed_streams++;
+                       unnamed_stream_idx = i;
+               }
+       }
+       if (num_unnamed_streams > 1) {
+               ERROR("Dentry `%s' has multiple (%u) un-named streams", 
+                     dentry->full_path_utf8, num_unnamed_streams);
+               goto out;
+       }
+
+#if 0
+       /* Check timestamps */
+       if (dentry->last_access_time < dentry->creation_time ||
+           dentry->last_write_time < dentry->creation_time) {
+               WARNING("Dentry `%s' was created after it was last accessed or "
+                     "written to", dentry->full_path_utf8);
+       }
+#endif
+
+       ret = 0;
+out:
+       return ret;
+}
+
 /* 
- * Writes a dentry to an output buffer.
+ * Writes a WIM dentry to an output buffer.
  *
  * @dentry:  The dentry structure.
  * @p:       The memory location to write the data to.
@@ -1106,7 +1367,13 @@ static u8 *write_dentry(const struct dentry *dentry, u8 *p)
        unsigned padding;
        const u8 *hash;
 
-       p = put_u64(p, dentry->length);
+       /* We calculate the correct length of the dentry ourselves because the
+        * dentry->length field may been set to an unexpected value from when we
+        * read the dentry in (for example, there may have been unknown data
+        * appended to the end of the dentry...) */
+       u64 length = dentry_correct_length(dentry);
+
+       p = put_u64(p, length);
        p = put_u32(p, dentry->attributes);
        p = put_u32(p, dentry->security_id);
        p = put_u64(p, dentry->subdir_offset);
@@ -1119,14 +1386,14 @@ static u8 *write_dentry(const struct dentry *dentry, u8 *p)
                hash = dentry->lte->hash;
        else
                hash = dentry->hash;
-       p = put_bytes(p, WIM_HASH_SIZE, hash);
+       p = put_bytes(p, SHA1_HASH_SIZE, hash);
        if (dentry->attributes & FILE_ATTRIBUTE_REPARSE_POINT) {
                p = put_zeroes(p, 4);
                p = put_u32(p, dentry->reparse_tag);
                p = put_zeroes(p, 4);
        } else {
                u64 hard_link;
-               p = put_u32(p, dentry->reparse_tag);
+               p = put_u32(p, 0);
                if (dentry->link_group_list.next == &dentry->link_group_list)
                        hard_link = 0;
                else
@@ -1136,53 +1403,67 @@ static u8 *write_dentry(const struct dentry *dentry, u8 *p)
        p = put_u16(p, dentry->num_ads);
        p = put_u16(p, dentry->short_name_len);
        p = put_u16(p, dentry->file_name_len);
-       p = put_bytes(p, dentry->file_name_len, (u8*)dentry->file_name);
-       p = put_u16(p, 0); /* filename padding, 2 bytes. */
-       p = put_bytes(p, dentry->short_name_len, (u8*)dentry->short_name);
-
-       wimlib_assert(p - orig_p <= dentry->length);
-       if (p - orig_p < dentry->length)
-               p = put_zeroes(p, dentry->length - (p - orig_p));
+       if (dentry->file_name_len) {
+               p = put_bytes(p, dentry->file_name_len, (u8*)dentry->file_name);
+               p = put_u16(p, 0); /* filename padding, 2 bytes. */
+       }
+       if (dentry->short_name) {
+               p = put_bytes(p, dentry->short_name_len, (u8*)dentry->short_name);
+               p = put_u16(p, 0); /* short name padding, 2 bytes */
+       }
 
-       p = put_zeroes(p, (8 - (p - orig_p) % 8) % 8);
+       /* Align to 8-byte boundary */
+       wimlib_assert(length >= (p - orig_p)
+                       && length - (p - orig_p) <= 7);
+       p = put_zeroes(p, length - (p - orig_p));
 
+       /* Write the alternate data streams, if there are any.  Please see
+        * read_ads_entries() for comments about the format of the on-disk
+        * alternate data stream entries. */
        for (u16 i = 0; i < dentry->num_ads; i++) {
-               p = put_u64(p, ads_entry_length(&dentry->ads_entries[i]));
+               p = put_u64(p, ads_entry_total_length(&dentry->ads_entries[i]));
                p = put_u64(p, 0); /* Unused */
-               p = put_bytes(p, WIM_HASH_SIZE, dentry->ads_entries[i].hash);
+               if (dentry->resolved && dentry->ads_entries[i].lte)
+                       hash = dentry->ads_entries[i].lte->hash;
+               else
+                       hash = dentry->ads_entries[i].hash;
+               p = put_bytes(p, SHA1_HASH_SIZE, hash);
                p = put_u16(p, dentry->ads_entries[i].stream_name_len);
-               p = put_bytes(p, dentry->ads_entries[i].stream_name_len,
-                                (u8*)dentry->ads_entries[i].stream_name);
+               if (dentry->ads_entries[i].stream_name_len) {
+                       p = put_bytes(p, dentry->ads_entries[i].stream_name_len,
+                                        (u8*)dentry->ads_entries[i].stream_name);
+                       p = put_u16(p, 0);
+               }
                p = put_zeroes(p, (8 - (p - orig_p) % 8) % 8);
        }
+#ifdef ENABLE_ASSERTIONS
+       wimlib_assert(p - orig_p == __dentry_total_length(dentry, length));
+#endif
        return p;
 }
 
-/* Recursive function that writes a dentry tree rooted at @tree, not including
- * @tree itself, which has already been written, except in the case of the root
- * dentry, which is written right away, along with an end-of-directory entry. */
-u8 *write_dentry_tree(const struct dentry *tree, u8 *p)
+/* Recursive function that writes a dentry tree rooted at @parent, not including
+ * @parent itself, which has already been written. */
+static u8 *write_dentry_tree_recursive(const struct dentry *parent, u8 *p)
 {
        const struct dentry *child;
 
-       if (dentry_is_root(tree)) {
-               p = write_dentry(tree, p);
-
-               /* write end of directory entry */
-               p = put_u64(p, 0);
-       } else {
-               /* Nothing to do for non-directories */
-               if (!dentry_is_directory(tree))
-                       return p;
-       }
+       /* Nothing to do if this dentry has no children. */
+       if (parent->subdir_offset == 0)
+               return p;
 
-       /* Write child dentries and end-of-directory entry. */
-       child = tree->children;
+       /* Write child dentries and end-of-directory entry. 
+        *
+        * Note: we need to write all of this dentry's children before
+        * recursively writing the directory trees rooted at each of the child
+        * dentries, since the on-disk dentries for a dentry's children are
+        * always located at consecutive positions in the metadata resource! */
+       child = parent->children;
        if (child) {
                do {
                        p = write_dentry(child, p);
                        child = child->next;
-               } while (child != tree->children);
+               } while (child != parent->children);
        }
 
        /* write end of directory entry */
@@ -1191,20 +1472,46 @@ u8 *write_dentry_tree(const struct dentry *tree, u8 *p)
        /* Recurse on children. */
        if (child) {
                do {
-                       p = write_dentry_tree(child, p);
+                       p = write_dentry_tree_recursive(child, p);
                        child = child->next;
-               } while (child != tree->children);
+               } while (child != parent->children);
        }
        return p;
 }
 
+/* Writes a directory tree to the metadata resource.
+ *
+ * @root:      Root of the dentry tree.
+ * @p:         Pointer to a buffer with enough space for the dentry tree.
+ *
+ * Returns pointer to the byte after the last byte we wrote.
+ */
+u8 *write_dentry_tree(const struct dentry *root, u8 *p)
+{
+       wimlib_assert(dentry_is_root(root));
+
+       /* If we're the root dentry, we have no parent that already
+        * wrote us, so we need to write ourselves. */
+       p = write_dentry(root, p);
+
+       /* Write end of directory entry after the root dentry just to be safe;
+        * however the root dentry obviously cannot have any siblings. */
+       p = put_u64(p, 0);
+
+       /* Recursively write the rest of the dentry tree. */
+       return write_dentry_tree_recursive(root, p);
+}
+
 /* Reads the children of a dentry, and all their children, ..., etc. from the
  * metadata resource and into the dentry tree.
  *
  * @metadata_resource: An array that contains the uncompressed metadata
  *                     resource for the WIM file.
- * @metadata_resource_len:     The length of @metadata_resource.
- * @dentry:    A pointer to a struct dentry that is the root of the directory
+ *
+ * @metadata_resource_len:  The length of the uncompressed metadata resource, in
+ *                         bytes.
+ *
+ * @dentry:    A pointer to a `struct dentry' that is the root of the directory
  *             tree and has already been read from the metadata resource.  It
  *             does not need to be the real root because this procedure is
  *             called recursively.
@@ -1221,8 +1528,12 @@ int read_dentry_tree(const u8 metadata_resource[], u64 metadata_resource_len,
        struct dentry cur_child;
        int ret;
 
-       /* If @dentry is a regular file, nothing more needs to be done for this
-        * branch. */
+       /* 
+        * If @dentry has no child dentries, nothing more needs to be done for
+        * this branch.  This is the case for regular files, symbolic links, and
+        * *possibly* empty directories (although an empty directory may also
+        * have one child dentry that is the special end-of-directory dentry)
+        */
        if (cur_offset == 0)
                return 0;
 
@@ -1236,10 +1547,8 @@ int read_dentry_tree(const u8 metadata_resource[], u64 metadata_resource_len,
                        break;
 
                /* Check for end of directory. */
-               if (cur_child.length == 0) {
-                       ret = 0;
+               if (cur_child.length == 0)
                        break;
-               }
 
                /* Not end of directory.  Allocate this child permanently and
                 * link it to the parent and previous child. */
@@ -1271,12 +1580,16 @@ int read_dentry_tree(const u8 metadata_resource[], u64 metadata_resource_len,
                                break;
                }
 
-               /* Advance to the offset of the next child. */
+               /* Advance to the offset of the next child.  Note: We need to
+                * advance by the TOTAL length of the dentry, not by the length
+                * child->length, which although it does take into account the
+                * padding, it DOES NOT take into account alternate stream
+                * entries. */
                cur_offset += dentry_total_length(child);
        }
 
-       /* Link last child to first one, and set parent's
-        * children pointer to the first child.  */
+       /* Link last child to first one, and set parent's children pointer to
+        * the first child.  */
        if (prev_child) {
                prev_child->next = first_child;
                first_child->prev = prev_child;