X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/2d41264e9ef645be0337ea64a398de2e563a4287..a41a1e87182410ec6c2eeaddb0cd961ec554c404:/util.c

diff --git a/util.c b/util.c
index 5243c746..4f1b59ac 100644
--- a/util.c
+++ b/util.c
@@ -197,7 +197,7 @@ int create_directory_path(char *fname, int base_umask)
  *
  * Derived from GNU C's cccp.c.
  */
-static int full_write(int desc, char *ptr, size_t len)
+int full_write(int desc, char *ptr, size_t len)
 {
 	int total_written;
 
@@ -245,7 +245,7 @@ static int safe_read(int desc, char *ptr, size_t len)
 
 /** Copy a file.
  *
- * This is used in conjunction with the --temp-dir option */
+ * This is used in conjunction with the --temp-dir and --backup options */
 int copy_file(char *source, char *dest, mode_t mode)
 {
 	int ifd;
@@ -664,11 +664,11 @@ int count_dir_elements(const char *p)
 	return cnt;
 }
 
-/* Turns multiple adjacent slashes into a single slash; gets rid of "./"
- * elements; collapses ".." elements except for those at the start of the
- * string; removes a trailing slash.  If the resulting name would be empty,
- * change it into a ".". */
-unsigned int clean_fname(char *name)
+/* Turns multiple adjacent slashes into a single slash, gets rid of "./"
+ * elements (but not a trailing dot dir), removes a trailing slash, and
+ * optionally collapses ".." elements (except for those at the start of the
+ * string).  If the resulting name would be empty, change it into a ".". */
+unsigned int clean_fname(char *name, BOOL collapse_dot_dot)
 {
 	char *limit = name - 1, *t = name, *f = name;
 	int anchored;
@@ -691,7 +691,8 @@ unsigned int clean_fname(char *name)
 				continue;
 			}
 			/* collapse ".." dirs */
-			if (f[1] == '.' && (f[2] == '/' || !f[2])) {
+			if (collapse_dot_dot
+			    && f[1] == '.' && (f[2] == '/' || !f[2])) {
 				char *s = t - 1;
 				if (s == name && anchored) {
 					f += 2;
@@ -703,9 +704,7 @@ unsigned int clean_fname(char *name)
 					f += 2;
 					continue;
 				}
-				*t++ = *f++;
-				*t++ = *f++;
-				limit = t;
+				limit = t + 2;
 			}
 		}
 		while (*f && (*t++ = *f++) != '/') {}
@@ -731,12 +730,17 @@ unsigned int clean_fname(char *name)
  * The rootdir string contains a value to use in place of a leading slash.
  * Specify NULL to get the default of lp_path(module_id).
  *
- * If depth is > 0, it is a count of how many '..'s to allow at the start
- * of the path.
+ * If depth is >= 0, it is a count of how many '..'s to allow at the start
+ * of the path.  Use -1 to allow unlimited depth.
  *
- * We call clean_fname() to clean up the path, but we preserve a trailing
- * slash because that is sometimes significant on command-line arguments.
- */
+ * We also clean the path in a manner similar to clean_fname() but with a
+ * few differences: 
+ *
+ * Turns multiple adjacent slashes into a single slash, gets rid of "." dir
+ * elements (INCLUDING a trailing dot dir), PRESERVES a trailing slash, and
+ * ALWAYS collapses ".." elements (except for those at the start of the
+ * string up to "depth" deep).  If the resulting name would be empty,
+ * change it into a ".". */
 char *sanitize_path(char *dest, const char *p, const char *rootdir, int depth)
 {
 	char *start, *sanp;
@@ -781,25 +785,22 @@ char *sanitize_path(char *dest, const char *p, const char *rootdir, int depth)
 		}
 		if (*p == '.' && p[1] == '.' && (p[2] == '/' || p[2] == '\0')) {
 			/* ".." component followed by slash or end */
-			if (depth > 0 && sanp == start) {
-				/* allow depth levels of .. at the beginning */
-				--depth;
-				*sanp++ = *p++;
-				*sanp++ = *p++;
-				/* move virtual beginning to leave .. alone */
-				start = sanp;
-				continue;
-			}
-			p += 2;
-			if (sanp != start) {
-				/* back up sanp one level */
-				--sanp; /* now pointing at slash */
-				while (sanp > start && sanp[-1] != '/') {
-					/* skip back up to slash */
-					sanp--;
+			if (depth <= 0 || sanp != start) {
+				p += 2;
+				if (sanp != start) {
+					/* back up sanp one level */
+					--sanp; /* now pointing at slash */
+					while (sanp > start && sanp[-1] != '/') {
+						/* skip back up to slash */
+						sanp--;
+					}
 				}
+				continue;
 			}
-			continue;
+			/* allow depth levels of .. at the beginning */
+			depth--;
+			/* move the virtual beginning to leave the .. alone */
+			start = sanp + 3;
 		}
 		/* copy one component through next slash */
 		while (*p && (*sanp++ = *p++) != '/') {}
@@ -854,7 +855,7 @@ int push_dir(char *dir)
 		curr_dir_len += len;
 	}
 
-	curr_dir_len = clean_fname(curr_dir);
+	curr_dir_len = clean_fname(curr_dir, 1);
 
 	return 1;
 }