From c9d8817a296d21ae2fc79d55bef5310c301e4f12 Mon Sep 17 00:00:00 2001
From: Marijn Haverbeke <marijnh@gmail.com>
Date: Fri, 18 Feb 2011 11:06:23 +0100
Subject: [PATCH] ff mac does not have integer charwidth. compensate for this

---
 lib/codemirror.js | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/lib/codemirror.js b/lib/codemirror.js
index 1dca8ff20a..3f3c89d9fd 100644
--- a/lib/codemirror.js
+++ b/lib/codemirror.js
@@ -372,7 +372,8 @@ var CodeMirror = (function() {
     div.className = "CodeMirror";
     div.innerHTML =
       '<div style="position: relative">' +
-        '<pre style="position: absolute; visibility: hidden"><span>-</span></pre>' +
+        '<pre style="position: absolute; visibility: hidden">' + 
+           '<span>xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx</span></pre>' +
         '<div style="position: relative">' +
           '<div class="CodeMirror-gutter"></div>' +
           '<div style="overflow: hidden; position: absolute; width: 0">' +
@@ -1133,12 +1134,13 @@ var CodeMirror = (function() {
     }
 
     function charX(line, pos) {
-      var text = lines[line].text;
+      var text = lines[line].text, span = measure.firstChild;
       if (text.lastIndexOf("\t", pos) == -1) return pos * charWidth();
+      var old = span.firstChild.nodeValue;
       try {
-        measure.firstChild.firstChild.nodeValue = text.slice(0, pos);
-        return measure.firstChild.offsetWidth;
-      } finally {measure.firstChild.firstChild.nodeValue = "-";}
+        span.firstChild.nodeValue = text.slice(0, pos);
+        return span.offsetWidth;
+      } finally {span.firstChild.nodeValue = old;}
     }
     function charFromX(line, x) {
       var text = lines[line].text, cw = charWidth();
@@ -1169,7 +1171,7 @@ var CodeMirror = (function() {
       if (nlines) return lineDiv.offsetHeight / nlines;
       else return measure.offsetHeight || 1;
     }
-    function charWidth() {return measure.firstChild.offsetWidth || 1;}
+    function charWidth() {return (measure.firstChild.offsetWidth || 320) / 40;}
     function paddingTop() {return lineWrap.offsetTop;}
     function paddingLeft() {return lineWrap.offsetLeft;}