PR29142, segv in ar with empty archive and libdeps specified

[Alan Modra <amodra@gmail.com>]

	PR 29142
	* ar.c (main): Properly handle libdeps for zero file_count.

diff --git a/binutils/ar.c b/binutils/ar.c
index 0d4c7cf16a6..6f3f1d6946f 100644
--- a/binutils/ar.c
+++ b/binutils/ar.c
@@ -894,14 +894,16 @@ main (int argc, char **argv)
 	     being operated on.  We shouldn't use 1st slot, but we want
 	     to avoid having to search all the way to the end of an
 	     archive with a large number of members at link time.  */
-	  new_files = xmalloc ((file_count + 2) * sizeof (char *));
-	  new_files[0] = files[0];
-	  new_files[1] = LIBDEPS;
-	  for (i = 1; i < file_count; i++)
-	    new_files[i+1] = files[i];
-	  file_count = ++i;
+	  new_files = xmalloc ((file_count + 2) * sizeof (*new_files));
+	  if (file_count)
+	    {
+	      new_files[0] = files[0];
+	      memcpy (new_files + 1, files, file_count * sizeof (*files));
+	    }
+	  new_files[file_count != 0] = LIBDEPS;
+	  file_count++;
+	  new_files[file_count] = NULL;
 	  files = new_files;
-	  files[i] = NULL;
 	}
 
       switch (operation)

-- 
Alan Modra
Australia Development Lab, IBM