* libc/argz/argz_add_sep.c (argz_add_sep): Handle empty string

	argument.
	* libc/argz/argz_append.c (argz_append): Handle empty buf argument.
	* libc/argz/argz_create_sep.c (argz_create_sep): Return (NULL, 0)
	on empty input strings.
	* libc/argz/argz_extract.c (argz_extract): Check argz_len before
	looping through argz.
	* libc/argz/argz_stringify.c (argz_stringify): Ditto.

1 files changed, 9 insertions, 8 deletions

diff --git a/newlib/libc/argz/argz_extract.c b/newlib/libc/argz/argz_extract.c
index 289c6e100..56c604684 100644
--- a/newlib/libc/argz/argz_extract.c
+++ b/newlib/libc/argz/argz_extract.c
@@ -17,14 +17,15 @@ _DEFUN (argz_extract, (argz, argz_len, argv),
   int j = 0;
   const size_t count = argz_count(argz, argz_len);
 
-  for (i = argz_len - 2; i > 0; i--)
-    {
-      if (argz[i] == '\0')
-        {
-          j++;
-          argv[count - j] = &argz[i + 1];
-        }
-    }
+  if (argz_len > 1)
+    for (i = argz_len - 2; i > 0; i--)
+      {
+	if (argz[i] == '\0')
+	  {
+	    j++;
+	    argv[count - j] = &argz[i + 1];
+	  }
+      }
   argv[0] = &argz[0];
   argv[count] = NULL;
 }