[glib] Add g_str_is_ascii()

[Ryan Lortie <desrt src gnome org>]

commit 4c510801cfc8120d7dea7ae8121832e8d17d2453
Author: Ryan Lortie <desrt desrt ca>
Date:   Mon Oct 14 14:36:34 2013 -0400

    Add g_str_is_ascii()
    
    Add a function for checking if a string is pure ASCII.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=709753

 docs/reference/glib/glib-sections.txt |    1 +
 glib/gstrfuncs.c                      |   23 +++++++++++++++++++++++
 glib/gstrfuncs.h                      |    2 ++
 3 files changed, 26 insertions(+), 0 deletions(-)
---
diff --git a/docs/reference/glib/glib-sections.txt b/docs/reference/glib/glib-sections.txt
index 3b5170c..39c0814 100644
--- a/docs/reference/glib/glib-sections.txt
+++ b/docs/reference/glib/glib-sections.txt
@@ -1302,6 +1302,7 @@ g_vasprintf
 g_printf_string_upper_bound
 
 <SUBSECTION>
+g_str_is_ascii
 g_ascii_isalnum
 g_ascii_isalpha
 g_ascii_iscntrl
diff --git a/glib/gstrfuncs.c b/glib/gstrfuncs.c
index 4fcd91c..8303313 100644
--- a/glib/gstrfuncs.c
+++ b/glib/gstrfuncs.c
@@ -1528,6 +1528,29 @@ g_ascii_strup (const gchar *str,
 }
 
 /**
+ * g_str_is_ascii:
+ * @string: a string.
+ *
+ * Determines if a string is pure ASCII.  A string is pure ASCII if it
+ * contains no bytes with the high bit set.
+ *
+ * Returns: %TRUE if @string is ascii
+ *
+ * Since: 2.40
+ **/
+gboolean
+g_str_is_ascii (const gchar *string)
+{
+  gint i;
+
+  for (i = 0; string[i]; i++)
+    if (string[i] & 0x80)
+      return FALSE;
+
+  return TRUE;
+}
+
+/**
  * g_strdown:
  * @string: the string to convert.
  *
diff --git a/glib/gstrfuncs.h b/glib/gstrfuncs.h
index 510623a..43bc924 100644
--- a/glib/gstrfuncs.h
+++ b/glib/gstrfuncs.h
@@ -195,6 +195,8 @@ GLIB_AVAILABLE_IN_ALL
 gchar*                g_ascii_strup       (const gchar *str,
                                           gssize       len) G_GNUC_MALLOC;
 
+GLIB_AVAILABLE_IN_2_40
+gboolean              g_str_is_ascii      (const gchar *str);
 
 GLIB_DEPRECATED
 gint                  g_strcasecmp     (const gchar *s1,