[pango] Avoid some overhead in pango_default_break

[Matthias Clasen <matthiasc src gnome org>]

commit 0bb2b5f4cf2264591657d2e0aead00955f9deb64
Author: Matthias Clasen <mclasen redhat com>
Date:   Sun Sep 13 11:26:19 2015 -0400

    Avoid some overhead in pango_default_break
    
    We already have the Unicode type, so we can determine
    isspace without doing the full type determination again.

 pango/break.c |   18 ++++++++++++++----
 1 files changed, 14 insertions(+), 4 deletions(-)
---
diff --git a/pango/break.c b/pango/break.c
index 1cc735c..b4b3c82 100644
--- a/pango/break.c
+++ b/pango/break.c
@@ -639,10 +639,20 @@ pango_default_break (const gchar   *text,
          makes_hangul_syllable = (prev_end == this_start) || (prev_end + 1 == this_start);
        }
 
-      /* Can't just use the type here since isspace() doesn't
-       * correspond to a Unicode character type
-       */
-      attrs[i].is_white = g_unichar_isspace (wc);
+      switch (type)
+        {
+        case G_UNICODE_SPACE_SEPARATOR:
+        case G_UNICODE_LINE_SEPARATOR:
+        case G_UNICODE_PARAGRAPH_SEPARATOR:
+          attrs[i].is_white = TRUE;
+          break;
+        default:
+          if (wc == '\t' || wc == '\n' || wc == '\r' || wc == '\f')
+            attrs[i].is_white = TRUE;
+          else
+            attrs[i].is_white = FALSE;
+          break;
+        }
 
       /* Just few spaces have variable width. So explicitly mark them.
        */