X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=path.c;h=e332b504a6b8c6b229da2526c4f810b8d0fb9889;hb=a797b02f3925c4a6324472e2edaf4a58d4ffc097;hp=a074aea64921eb1fb90f079ede9087e6b8109f6a;hpb=b43b73666be32ecdc27384d67dc88e4b4869efa1;p=git.git

diff --git a/path.c b/path.c
index a074aea64..e332b504a 100644
--- a/path.c
+++ b/path.c
@@ -363,56 +363,97 @@ const char *make_relative_path(const char *abs, const char *base)
 }
 
 /*
- * path = absolute path
- * buf = buffer of at least max(2, strlen(path)+1) bytes
- * It is okay if buf == path, but they should not overlap otherwise.
+ * It is okay if dst == src, but they should not overlap otherwise.
  *
- * Performs the following normalizations on path, storing the result in buf:
- * - Removes trailing slashes.
- * - Removes empty components.
+ * Performs the following normalizations on src, storing the result in dst:
+ * - Ensures that components are separated by '/' (Windows only)
+ * - Squashes sequences of '/'.
  * - Removes "." components.
  * - Removes ".." components, and the components the precede them.
- * "" and paths that contain only slashes are normalized to "/".
- * Returns the length of the output.
+ * Returns failure (non-zero) if a ".." component appears as first path
+ * component anytime during the normalization. Otherwise, returns success (0).
  *
  * Note that this function is purely textual.  It does not follow symlinks,
  * verify the existence of the path, or make any system calls.
  */
-int normalize_absolute_path(char *buf, const char *path)
+int normalize_path_copy(char *dst, const char *src)
 {
-	const char *comp_start = path, *comp_end = path;
-	char *dst = buf;
-	int comp_len;
-	assert(buf);
-	assert(path);
-
-	while (*comp_start) {
-		assert(*comp_start == '/');
-		while (*++comp_end && *comp_end != '/')
-			; /* nothing */
-		comp_len = comp_end - comp_start;
-
-		if (!strncmp("/",  comp_start, comp_len) ||
-		    !strncmp("/.", comp_start, comp_len))
-			goto next;
-
-		if (!strncmp("/..", comp_start, comp_len)) {
-			while (dst > buf && *--dst != '/')
-				; /* nothing */
-			goto next;
-		}
+	char *dst0;
 
-		memmove(dst, comp_start, comp_len);
-		dst += comp_len;
-	next:
-		comp_start = comp_end;
+	if (has_dos_drive_prefix(src)) {
+		*dst++ = *src++;
+		*dst++ = *src++;
 	}
+	dst0 = dst;
 
-	if (dst == buf)
+	if (is_dir_sep(*src)) {
 		*dst++ = '/';
+		while (is_dir_sep(*src))
+			src++;
+	}
 
+	for (;;) {
+		char c = *src;
+
+		/*
+		 * A path component that begins with . could be
+		 * special:
+		 * (1) "." and ends   -- ignore and terminate.
+		 * (2) "./"           -- ignore them, eat slash and continue.
+		 * (3) ".." and ends  -- strip one and terminate.
+		 * (4) "../"          -- strip one, eat slash and continue.
+		 */
+		if (c == '.') {
+			if (!src[1]) {
+				/* (1) */
+				src++;
+			} else if (is_dir_sep(src[1])) {
+				/* (2) */
+				src += 2;
+				while (is_dir_sep(*src))
+					src++;
+				continue;
+			} else if (src[1] == '.') {
+				if (!src[2]) {
+					/* (3) */
+					src += 2;
+					goto up_one;
+				} else if (is_dir_sep(src[2])) {
+					/* (4) */
+					src += 3;
+					while (is_dir_sep(*src))
+						src++;
+					goto up_one;
+				}
+			}
+		}
+
+		/* copy up to the next '/', and eat all '/' */
+		while ((c = *src++) != '\0' && !is_dir_sep(c))
+			*dst++ = c;
+		if (is_dir_sep(c)) {
+			*dst++ = '/';
+			while (is_dir_sep(c))
+				c = *src++;
+			src--;
+		} else if (!c)
+			break;
+		continue;
+
+	up_one:
+		/*
+		 * dst0..dst is prefix portion, and dst[-1] is '/';
+		 * go up one level.
+		 */
+		dst--;	/* go to trailing '/' */
+		if (dst <= dst0)
+			return -1;
+		/* Windows: dst[-1] cannot be backslash anymore */
+		while (dst0 < dst && dst[-1] != '/')
+			dst--;
+	}
 	*dst = '\0';
-	return dst - buf;
+	return 0;
 }
 
 /*
@@ -438,15 +479,16 @@ int longest_ancestor_length(const char *path, const char *prefix_list)
 		return -1;
 
 	for (colon = ceil = prefix_list; *colon; ceil = colon+1) {
-		for (colon = ceil; *colon && *colon != ':'; colon++);
+		for (colon = ceil; *colon && *colon != PATH_SEP; colon++);
 		len = colon - ceil;
 		if (len == 0 || len > PATH_MAX || !is_absolute_path(ceil))
 			continue;
 		strlcpy(buf, ceil, len+1);
-		len = normalize_absolute_path(buf, buf);
-		/* Strip "trailing slashes" from "/". */
-		if (len == 1)
-			len = 0;
+		if (normalize_path_copy(buf, buf) < 0)
+			continue;
+		len = strlen(buf);
+		if (len > 0 && buf[len-1] == '/')
+			buf[--len] = '\0';
 
 		if (!strncmp(path, buf, len) &&
 		    path[len] == '/' &&
@@ -457,3 +499,39 @@ int longest_ancestor_length(const char *path, const char *prefix_list)
 
 	return max_len;
 }
+
+/* strip arbitrary amount of directory separators at end of path */
+static inline int chomp_trailing_dir_sep(const char *path, int len)
+{
+	while (len && is_dir_sep(path[len - 1]))
+		len--;
+	return len;
+}
+
+/*
+ * If path ends with suffix (complete path components), returns the
+ * part before suffix (sans trailing directory separators).
+ * Otherwise returns NULL.
+ */
+char *strip_path_suffix(const char *path, const char *suffix)
+{
+	int path_len = strlen(path), suffix_len = strlen(suffix);
+
+	while (suffix_len) {
+		if (!path_len)
+			return NULL;
+
+		if (is_dir_sep(path[path_len - 1])) {
+			if (!is_dir_sep(suffix[suffix_len - 1]))
+				return NULL;
+			path_len = chomp_trailing_dir_sep(path, path_len);
+			suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
+		}
+		else if (path[--path_len] != suffix[--suffix_len])
+			return NULL;
+	}
+
+	if (path_len && !is_dir_sep(path[path_len - 1]))
+		return NULL;
+	return xstrndup(path, chomp_trailing_dir_sep(path, path_len));
+}