1 files changed, 45 insertions, 30 deletions

diff --git a/libbb/xreadlink.c b/libbb/xreadlink.c
index a18dd0748..2682f6975 100644
--- a/libbb/xreadlink.c
+++ b/libbb/xreadlink.c
@@ -123,7 +123,7 @@ char* FAST_FUNC xmalloc_realpath(const char *path)
 #endif
 }
 
-char* FAST_FUNC xmalloc_realpath_coreutils(const char *path)
+char* FAST_FUNC xmalloc_realpath_coreutils(char *path)
 {
 	char *buf;
 
@@ -137,32 +137,19 @@ char* FAST_FUNC xmalloc_realpath_coreutils(const char *path)
 	 * (the directory must exist).
 	 */
 	if (!buf && errno == ENOENT) {
-		char *last_slash = strrchr(path, '/');
-		if (last_slash) {
-			*last_slash++ = '\0';
-			buf = xmalloc_realpath(path);
-			if (buf) {
-				unsigned len = strlen(buf);
-				buf = xrealloc(buf, len + strlen(last_slash) + 2);
-				buf[len++] = '/';
-				strcpy(buf + len, last_slash);
-			}
-		} else {
-			char *target = xmalloc_readlink(path);
-			if (target) {
-				char *cwd;
-				if (target[0] == '/') {
-					/*
-					 * $ ln -s /bin/qwe symlink  # note: /bin is a link to /usr/bin
-					 * $ readlink -f symlink
-					 * /usr/bin/qwe/target_does_not_exist
-					 * $ realpath symlink
-					 * /usr/bin/qwe/target_does_not_exist
-					 */
-					buf = xmalloc_realpath_coreutils(target);
-					free(target);
-					return buf;
-				}
+		char *target, c, *last_slash;
+		size_t i;
+
+		target = xmalloc_readlink(path);
+		if (target) {
+			/*
+			 * $ ln -s /bin/qwe symlink  # note: /bin is a link to /usr/bin
+			 * $ readlink -f symlink
+			 * /usr/bin/qwe
+			 * $ realpath symlink
+			 * /usr/bin/qwe
+			 */
+			if (target[0] != '/') {
 				/*
 				 * $ ln -s target_does_not_exist symlink
 				 * $ readlink -f symlink
@@ -170,13 +157,41 @@ char* FAST_FUNC xmalloc_realpath_coreutils(const char *path)
 				 * $ realpath symlink
 				 * /CURDIR/target_does_not_exist
 				 */
-				cwd = xrealloc_getcwd_or_warn(NULL);
-				buf = concat_path_file(cwd, target);
+				char *cwd = xrealloc_getcwd_or_warn(NULL);
+				char *tmp = concat_path_file(cwd, target);
 				free(cwd);
 				free(target);
-				return buf;
+				target = tmp;
+			}
+			buf = xmalloc_realpath_coreutils(target);
+			free(target);
+			return buf;
+		}
+
+		/* ignore leading and trailing slashes */
+		while (path[0] == '/' && path[1] == '/')
+			++path;
+		i = strlen(path) - 1;
+		while (i > 0 && path[i] == '/')
+			i--;
+		c = path[i + 1];
+		path[i + 1] = '\0';
+
+		last_slash = strrchr(path, '/');
+		if (last_slash == path)
+			buf = xstrdup(path);
+		else if (last_slash) {
+			*last_slash = '\0';
+			buf = xmalloc_realpath(path);
+			*last_slash++ = '/';
+			if (buf) {
+				unsigned len = strlen(buf);
+				buf = xrealloc(buf, len + strlen(last_slash) + 2);
+				buf[len++] = '/';
+				strcpy(buf + len, last_slash);
 			}
 		}
+		path[i + 1] = c;
 	}
 
 	return buf;