Metadata resource compatibility

[wimlib] / src / lookup_table.c

diff --git a/src/lookup_table.c b/src/lookup_table.c
index 1226488acebee959713f8cbbd9a89287c9334c6f..3d66ca18246be543cb63037d34af60989a0cb1f8 100644 (file)
--- a/src/lookup_table.c
+++ b/src/lookup_table.c
@@ -59,7 +59,7 @@ err:
 struct lookup_table_entry *new_lookup_table_entry()
 {
        struct lookup_table_entry *lte;
-       
+
        lte = CALLOC(1, sizeof(struct lookup_table_entry));
        if (lte) {
                lte->part_number  = 1;
@@ -185,7 +185,7 @@ void free_lookup_table(struct lookup_table *table)
  * @table:     A pointer to the lookup table.
  * @entry:     A pointer to the entry to insert.
  */
-void lookup_table_insert(struct lookup_table *table, 
+void lookup_table_insert(struct lookup_table *table,
                         struct lookup_table_entry *lte)
 {
        size_t i = lte->hash_short % table->capacity;
@@ -237,11 +237,11 @@ void lte_decrement_num_opened_fds(struct lookup_table_entry *lte,
 }
 #endif
 
-/* 
+/*
  * Calls a function on all the entries in the lookup table.  Stop early and
  * return nonzero if any call to the function returns nonzero.
  */
-int for_lookup_table_entry(struct lookup_table *table, 
+int for_lookup_table_entry(struct lookup_table *table,
                           int (*visitor)(struct lookup_table_entry *, void *),
                           void *arg)
 {
@@ -311,7 +311,7 @@ int read_lookup_table(WIMStruct *w)
                }
                cur_entry->wim = w;
                cur_entry->resource_location = RESOURCE_IN_WIM;
-                        
+
                p = get_resource_entry(buf, &cur_entry->resource_entry);
                p = get_u16(p, &cur_entry->part_number);
                p = get_u32(p, &cur_entry->refcnt);
@@ -332,8 +332,15 @@ int read_lookup_table(WIMStruct *w)
                        goto out_free_cur_entry;
                }
 
+               /* Ordinarily, no two streams should share the same SHA1 message
+                * digest.  However, this constraint can be broken for metadata
+                * resources--- two identical images will have the same metadata
+                * resource, but their lookup table entries are not shared. */
                duplicate_entry = __lookup_resource(table, cur_entry->hash);
-               if (duplicate_entry) {
+               if (duplicate_entry
+                   && !((duplicate_entry->resource_entry.flags & WIM_RESHDR_FLAG_METADATA)
+                         && cur_entry->resource_entry.flags & WIM_RESHDR_FLAG_METADATA))
+               {
                        ERROR("The WIM lookup table contains two entries with the "
                              "same SHA1 message digest!");
                        ERROR("The first entry is:");
@@ -369,7 +376,7 @@ out:
 }
 
 
-/* 
+/*
  * Writes a lookup table entry to the output file.
  */
 int write_lookup_table_entry(struct lookup_table_entry *lte, void *__out)
@@ -426,11 +433,11 @@ void print_lookup_table_entry(const struct lookup_table_entry *lte)
                putchar('\n');
                return;
        }
-       printf("Offset            = %"PRIu64" bytes\n", 
+       printf("Offset            = %"PRIu64" bytes\n",
               lte->resource_entry.offset);
-       printf("Size              = %"PRIu64" bytes\n", 
+       printf("Size              = %"PRIu64" bytes\n",
               (u64)lte->resource_entry.size);
-       printf("Original size     = %"PRIu64" bytes\n", 
+       printf("Original size     = %"PRIu64" bytes\n",
               lte->resource_entry.original_size);
        printf("Part Number       = %hu\n", lte->part_number);
        printf("Reference Count   = %u\n", lte->refcnt);
@@ -475,16 +482,16 @@ static int do_print_lookup_table_entry(struct lookup_table_entry *lte,
 }
 
 /*
- * Prints the lookup table of a WIM file. 
+ * Prints the lookup table of a WIM file.
  */
 WIMLIBAPI void wimlib_print_lookup_table(WIMStruct *w)
 {
-       for_lookup_table_entry(w->lookup_table, 
+       for_lookup_table_entry(w->lookup_table,
                               do_print_lookup_table_entry,
                               NULL);
 }
 
-/* 
+/*
  * Looks up an entry in the lookup table.
  */
 struct lookup_table_entry *
@@ -505,7 +512,7 @@ __lookup_resource(const struct lookup_table *table, const u8 hash[])
 }
 
 #ifdef WITH_FUSE
-/* 
+/*
  * Finds the dentry, lookup table entry, and stream index for a WIM file stream,
  * given a path name.
  *
@@ -610,7 +617,7 @@ static void inode_unresolve_ltes(struct inode *inode)
        inode->resolved = false;
 }
 
-/* Resolve a dentry's lookup table entries 
+/* Resolve a dentry's lookup table entries
  *
  * This replaces the SHA1 hash fields (which are used to lookup an entry in the
  * lookup table) with pointers directly to the lookup table entries.  A circular