Canonicalize dirname(3) behavior.

3 files changed, 17 insertions, 9 deletions

diff --git a/libbb/dirname.c b/libbb/dirname.c
index 5f839945d..87db1f24f 100644
--- a/libbb/dirname.c
+++ b/libbb/dirname.c
@@ -22,7 +22,8 @@
 #include <string.h>
 #include "libbb.h"
 
-/* Return a string on the heap containing the directory component of PATH.  */
+/* Return a string containing the path name of the parent
+ * directory of PATH.  */
 
 char *dirname(const char *path)
 {
@@ -43,7 +44,8 @@ char *dirname(const char *path)
                 s--;
 
         if (s < path)
-                return xstrdup (".");
-        else
-                return xstrndup (path, s - path + 1);
+                return ".";
+
+        s[1] = '\0';
+        return path;
 }
diff --git a/libbb/make_directory.c b/libbb/make_directory.c
index 7b7fde911..a06a410d2 100644
--- a/libbb/make_directory.c
+++ b/libbb/make_directory.c
@@ -50,13 +50,17 @@ int make_directory (char *path, long mode, int flags)
 
                 if (stat (path, &st) < 0 && errno == ENOENT) {
                         int status;
-                        char *parent = dirname (path);
-                        mode_t mask = umask (0);
+                        char *buf, *parent;
+                        mode_t mask;
+
+                        mask = umask (0);
                         umask (mask);
 
+                        buf = xstrdup (path);
+                        parent = dirname (buf);
                         status = make_directory (parent, (0777 & ~mask) | 0300,
                                         FILEUTILS_RECUR);
-                        free (parent);
+                        free (buf);
 
                         if (status < 0 || make_directory (path, mode, 0) < 0)
                                 return -1;
diff --git a/libbb/unarchive.c b/libbb/unarchive.c
index 0d414a3a8..2d171b4ce 100644
--- a/libbb/unarchive.c
+++ b/libbb/unarchive.c
@@ -127,13 +127,15 @@ char *extract_archive(FILE *src_stream, FILE *out_stream, const file_header_t *f
                         }
                 }
                 if (function & extract_create_leading_dirs) { /* Create leading directories with default umask */
-                        char *parent = dirname(full_name);
+                        char *buf, *parent;
+                        buf = xstrdup(full_name);
+                        parent = dirname(full_name);
                         if (make_directory (parent, -1, FILEUTILS_RECUR) != 0) {
                                 if ((function & extract_quiet) != extract_quiet) {
                                         error_msg("couldn't create leading directories");
                                 }
                         }
-                        free (parent);
+                        free (buf);
                 }
                 switch(file_entry->mode & S_IFMT) {
                         case S_IFREG: