PBWebGit: Fix display of commit message when there is no diff

This happens for example in conflictless merge commits.

Author: pieter

html/commit.js

@@ -3,8 +3,16 @@ var Commit = Class.create({
 	initialize: function(obj) {
 		this.raw = obj.details;
 
-		var messageStart = this.raw.indexOf("\n\n") + 2;
 		var diffStart = this.raw.indexOf("\ndiff ");
+		var messageStart = this.raw.indexOf("\n\n") + 2;
+
+		if (diffStart > 0) {
+			this.message = this.raw.substring(messageStart, diffStart);
+			this.diff = this.raw.substring(diffStart)
+		} else {
+			this.message = this.raw.substring(messageStart)
+			this.diff = ""
+		}
 		this.header = this.raw.substring(0, messageStart);
 
 		this.sha = this.header.match(/^commit ([0-9a-f]{40,40})/)[1];
@@ -23,8 +31,6 @@ var Commit = Class.create({
 			return x.replace("\nparent ",""); 
 		});
 
-		this.message = this.raw.substring(messageStart, diffStart);
-		this.diff = this.raw.substring(diffStart);
 	},	
 });
 
@@ -59,6 +65,7 @@ var doeHet = function() {
 	});
 
 	$("message").innerHTML = commit.message.replace(/\n/g,"<br>");
+
 	if (commit.diff.length < 10000) {
 		showDiffs();
 	} else {