From ee9c70ab7f59f1c035aa9ea1982bf9c999d2e57e Mon Sep 17 00:00:00 2001
From: "Edward Z. Yang" <ezyang@mit.edu>
Date: Thu, 17 Mar 2011 17:33:11 +0000
Subject: [PATCH] Fix E_NOTICE from indexing into empty string.

Signed-off-by: Edward Z. Yang <ezyang@mit.edu>
---
 NEWS                                       |  2 ++
 library/HTMLPurifier/TagTransform/Font.php | 16 +++++++++-------
 tests/HTMLPurifier/TagTransformTest.php    |  4 ++++
 3 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/NEWS b/NEWS
index 4d1ff862..486860d0 100644
--- a/NEWS
+++ b/NEWS
@@ -43,6 +43,8 @@ NEWS ( CHANGELOG and HISTORY )                                     HTMLPurifier
   Reported by Neike Taika-Tessaro.
 - Fix missing numeric entities on DirectLex; thanks Neike Taika-Tessaro
   for reporting.
+- Fix harmless notice from indexing into empty string.  Thanks Matthijs
+  Kooijman <matthijs@stdin.nl> for reporting.
 
 4.2.0, released 2010-09-15
 ! Added %Core.RemoveProcessingInstructions, which lets you remove
diff --git a/library/HTMLPurifier/TagTransform/Font.php b/library/HTMLPurifier/TagTransform/Font.php
index ed246378..9db2db79 100644
--- a/library/HTMLPurifier/TagTransform/Font.php
+++ b/library/HTMLPurifier/TagTransform/Font.php
@@ -63,13 +63,15 @@ class HTMLPurifier_TagTransform_Font extends HTMLPurifier_TagTransform
         // handle size transform
         if (isset($attr['size'])) {
             // normalize large numbers
-            if ($attr['size']{0} == '+' || $attr['size']{0} == '-') {
-                $size = (int) $attr['size'];
-                if ($size < -2) $attr['size'] = '-2';
-                if ($size > 4)  $attr['size'] = '+4';
-            } else {
-                $size = (int) $attr['size'];
-                if ($size > 7) $attr['size'] = '7';
+            if ($attr['size'] !== '') {
+                if ($attr['size']{0} == '+' || $attr['size']{0} == '-') {
+                    $size = (int) $attr['size'];
+                    if ($size < -2) $attr['size'] = '-2';
+                    if ($size > 4)  $attr['size'] = '+4';
+                } else {
+                    $size = (int) $attr['size'];
+                    if ($size > 7) $attr['size'] = '7';
+                }
             }
             if (isset($this->_size_lookup[$attr['size']])) {
                 $prepend_style .= 'font-size:' .
diff --git a/tests/HTMLPurifier/TagTransformTest.php b/tests/HTMLPurifier/TagTransformTest.php
index 2e351016..8669d5b9 100644
--- a/tests/HTMLPurifier/TagTransformTest.php
+++ b/tests/HTMLPurifier/TagTransformTest.php
@@ -162,6 +162,10 @@ class HTMLPurifier_TagTransformTest extends HTMLPurifier_Harness
         $this->assertSizeToStyle($transformer, '+3', '200%');
         $this->assertSizeToStyle($transformer, '+4', '300%');
         $this->assertSizeToStyle($transformer, '+5', '300%');
+        $this->assertTransformation(
+            $transformer, 'font', array('size' => ''),
+            'span', array()
+        );
 
         // test multiple transforms, the alphabetical ordering is important
         $this->assertTransformation(
-- 
2.11.4.GIT