docs: fix the 'view source' button for snapshots

Closes angular#5590
Closes angular#5641

docs/spec/ngdocSpec.js

@@ -1,5 +1,7 @@
 var ngdoc = require('../src/ngdoc.js');
 var DOM = require('../src/dom.js').DOM;
+var gruntUtil = require('../../lib/grunt/utils.js');
+
 
 describe('ngdoc', function() {
   var Doc = ngdoc.Doc;
@@ -287,6 +289,33 @@ describe('ngdoc', function() {
     });
   });
 
+
+  describe('api section', function() {
+
+    it('should render a "view source" button with link to the source in master', function() {
+      var doc = new Doc({
+        id: 'ng.abc',
+        name: 'ng.abc',
+        section: 'api',
+        ngdoc: 'service',
+        file: 'fooService.js',
+        line: '333'
+      });
+
+      if (gruntUtil.getVersion().full.indexOf('-') === -1) {
+        expect(doc.html().match(/^(<a .*?<\/a>)/)[1]).toMatch(
+          /<a href="http:\/\/github\.com\/angular\/angular\.js\/tree\/v\d+\.\d+\.\d+\/fooService\.js#L333" class="view-source/
+        );
+      } else {
+        expect(doc.html().match(/^(<a .*?<\/a>)/)[1]).toMatch(
+          /<a href="http:\/\/github\.com\/angular\/angular\.js\/tree\/[a-z0-9]{7}\/fooService\.js#L333" class="view-source/
+        );
+      }
+    });
+  });
+
+
+
   ////////////////////////////////////////
 
   describe('TAG', function() {

docs/src/ngdoc.js

@@ -552,7 +552,7 @@ Doc.prototype = {
       minerrMsg;
 
     var gitTagFromFullVersion = function(version) {
-      var match = version.match(/-(\w{7})/);
+      var match = version.match(/sha\.(\w{7})/);
 
       if (match) {
         // git sha