[glib] g_str_has_prefix: don't call strlen(str)

[Dan Winship <danw src gnome org>]

commit eec507c15987388ae624eada236032e700bf8c50
Author: Dan Winship <danw gnome org>
Date:   Wed Apr 9 09:57:46 2014 -0400

    g_str_has_prefix: don't call strlen(str)
    
    There's no reason to check the length of @str in g_str_has_prefix(),
    since if it's shorter than @prefix, the strncmp() will fail anyway.
    And besides making the function less efficient, it also breaks code
    like:
    
        if (buf->len >=3 && g_str_has_prefix (buf->data, "foo"))
          ...
    
    which really looks like it ought to work whether buf->data is
    nul-terminated or not.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=727890

 glib/gstrfuncs.c |   11 +----------
 1 files changed, 1 insertions(+), 10 deletions(-)
---
diff --git a/glib/gstrfuncs.c b/glib/gstrfuncs.c
index e9b13c5..0c50dfb 100644
--- a/glib/gstrfuncs.c
+++ b/glib/gstrfuncs.c
@@ -2794,19 +2794,10 @@ gboolean
 g_str_has_prefix (const gchar *str,
                   const gchar *prefix)
 {
-  int str_len;
-  int prefix_len;
-
   g_return_val_if_fail (str != NULL, FALSE);
   g_return_val_if_fail (prefix != NULL, FALSE);
 
-  str_len = strlen (str);
-  prefix_len = strlen (prefix);
-
-  if (str_len < prefix_len)
-    return FALSE;
-
-  return strncmp (str, prefix, prefix_len) == 0;
+  return strncmp (str, prefix, strlen (prefix)) == 0;
 }
 
 /**