Introduce wmem_ascii_strdown()

Change-Id: Icdc5a0d5033f3ab709fbf19a33ab26f609d4b1f0
Reviewed-on: https://code.wireshark.org/review/824
Reviewed-by: Evan Huus <eapache@gmail.com>

epan/wmem/wmem_strutl.c

@@ -200,6 +200,26 @@ wmem_strsplit(wmem_allocator_t *allocator, const gchar *src,
     return vec;
 }
 
+/*
+ * wmem_ascii_strdown:
+ * based on g_ascii_strdown.
+ */
+gchar*
+wmem_ascii_strdown(wmem_allocator_t *allocator, const gchar *str, gssize len)
+{
+    gchar *result, *s;
+
+    g_return_val_if_fail (str != NULL, NULL);
+
+    if (len < 0)
+        len = strlen (str);
+
+    result = wmem_strndup(allocator, str, len);
+    for (s = result; *s; s++)
+        *s = g_ascii_tolower (*s);
+
+    return result;
+}
 /*
  * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
  *

epan/wmem/wmem_strutl.h

@@ -76,6 +76,25 @@ gchar **
 wmem_strsplit(wmem_allocator_t *allocator, const gchar *src,
         const gchar *delimiter, int max_tokens);
 
+
+/**
+ * wmem_ascii_strdown:
+ * Based on g_ascii_strdown
+ * @allocator: An enumeration of the different types of available allocators.
+ * @str: a string.
+ * @len: length of @str in bytes, or -1 if @str is nul-terminated.
+ *
+ * Converts all upper case ASCII letters to lower case ASCII letters.
+ *
+ * Return value: a newly-allocated string, with all the upper case
+ *               characters in @str converted to lower case, with
+ *               semantics that exactly match g_ascii_tolower(). (Note
+ *               that this is unlike the old g_strdown(), which modified
+ *               the string in place.)
+ **/
+WS_DLL_PUBLIC
+gchar*
+wmem_ascii_strdown(wmem_allocator_t *allocator, const gchar *str, gssize len);
 /**   @}
  *  @} */
 

epan/wmem/wmem_test.c

@@ -435,6 +435,11 @@ wmem_test_strutls(void)
     g_assert_cmpstr(split_str[0], ==, "aslkf");
     g_assert_cmpstr(split_str[1], ==, "asio");
     g_assert_cmpstr(split_str[2], ==, "-asfj-as--");
+    wmem_strict_check_canaries(allocator);
+
+    orig_str = "TeStAsCiIsTrDoWn";
+    new_str = wmem_ascii_strdown(allocator, orig_str, -1);
+    g_assert_cmpstr(new_str, ==, "testasciistrdown");
 
     wmem_destroy_allocator(allocator);
 }