More logical behavior when canonicalizing WIM paths

[wimlib] / src / paths.c

diff --git a/src/paths.c b/src/paths.c
index 68942f20265862c40923ffe64ba64fc184ef3d32..675b9f2752a4e21746febd9a848821bcc37f875b 100644 (file)
--- a/src/paths.c
+++ b/src/paths.c
@@ -87,38 +87,63 @@ canonicalize_fs_path(const tchar *fs_path)
  * canonicalize_wim_path() - Given a user-provided path to a file within a WIM
  * image, translate it into a "canonical" path.
  *
- * To do this, translate all supported path separators (is_any_path_separator())
- * into the WIM_PATH_SEPARATOR, and strip any leading and trailing slashes.  The
- * returned string is allocated.  Note that there still may be consecutive path
- * separators within the string.  Furthermore, the string may be empty, which
- * indicates the root dentry of the WIM image.
+ * - Translate both types of slash into a consistent type (WIM_PATH_SEPARATOR).
+ * - Collapse path separators.
+ * - Add leading slash if missing.
+ * - Strip trailing slashes.
+ *
+ * Examples (with WIM_PATH_SEPARATOR == '/'):
+ *
+ *             => /            [ either NULL or empty string ]
+ * /           => /
+ * \           => /
+ * hello       => /hello
+ * \hello      => /hello
+ * \hello      => /hello
+ * /hello/     => /hello
+ * \hello/     => /hello
+ * /hello//1   => /hello/1
+ * \\hello\\1\\        => /hello/1
  */
 tchar *
 canonicalize_wim_path(const tchar *wim_path)
 {
-       tchar *canonical_path;
-       tchar *p;
-
-       if (wim_path == NULL) {
-               wim_path = T("");
-       } else {
-               /* Strip leading path separators.  */
-               while (is_any_path_separator(*wim_path))
-                       wim_path++;
-       }
+       const tchar *in;
+       tchar *out;
+       tchar *result;
 
-       canonical_path = TSTRDUP(wim_path);
-       if (canonical_path == NULL)
+       in = wim_path;
+       if (!in)
+               in = T("");
+
+       result = MALLOC((1 + tstrlen(in) + 1) * sizeof(result[0]));
+       if (!result)
                return NULL;
 
-       /* Translate all path separators to WIM_PATH_SEPARATOR.  */
-       for (p = canonical_path; *p; p++)
-               if (is_any_path_separator(*p))
-                       *p = WIM_PATH_SEPARATOR;
+       out = result;
+
+       /* Add leading slash if missing  */
+       if (!is_any_path_separator(*in))
+               *out++ = WIM_PATH_SEPARATOR;
+
+       while (*in) {
+               if (is_any_path_separator(*in)) {
+                       /* Collapse multiple path separators into one  */
+                       *out++ = WIM_PATH_SEPARATOR;
+                       do {
+                               in++;
+                       } while (is_any_path_separator(*in));
+               } else {
+                       /* Copy non-path-separator character  */
+                       *out++ = *in++;
+               }
+       }
+
+       /* Remove trailing slash if existent  */
+       if (*(out - 1) == WIM_PATH_SEPARATOR && (out - 1) != result)
+               --out;
 
-       /* Strip trailing path separators.  */
-       while (p > canonical_path && *--p == WIM_PATH_SEPARATOR)
-               *p = T('\0');
+       *out = T('\0');
 
-       return canonical_path;
+       return result;
 }