Avoid a segfault (detected by Fabio Ferrari

<fabio.ferrari@digitro.com.br> in the wget applet) when
concat_path_file() or last_char_is() were fed a NULL.
 -Erik

1 files changed, 5 insertions, 2 deletions

diff --git a/libbb/concat_path_file.c b/libbb/concat_path_file.c
index 61efa9c3e..c699a84f7 100644
--- a/libbb/concat_path_file.c
+++ b/libbb/concat_path_file.c
@@ -13,11 +13,14 @@ extern char *concat_path_file(const char *path, const char *filename)
 {
         char *outbuf;
         char *lc;
-        
+
+        if (!path)
+            path="";
         lc = last_char_is(path, '/');
         if (filename[0] == '/')
                 filename++;
         outbuf = xmalloc(strlen(path)+strlen(filename)+1+(lc==NULL));
-        sprintf(outbuf, (lc==NULL ? "%s/%s" : "%s%s"), path, filename);
+        sprintf(outbuf, "%s%s%s", path, (lc==NULL)? "/" : "", filename);
+
         return outbuf;
 }