Guard against missing file path in getScore()

CHANGELOG.md

@@ -1,3 +1,5 @@
+* Fixed: Error selecting a grammar for an untitled editor
+
 * Added: j/k now can be used to navigate the tree view and archive editor
 
 * Fixed: Atom can now be launched when ~/.atom/config.cson doesn't exist

spec/app/syntax-spec.coffee

@@ -75,6 +75,12 @@ describe "the `syntax` global", ->
 
         expect(syntax.selectGrammar('more.test', '')).toBe grammar1
 
+    describe "when there is no file path", ->
+      it "does not throw an exception (regression)", ->
+        expect(-> syntax.selectGrammar(null, '#!/usr/bin/ruby')).not.toThrow()
+        expect(-> syntax.selectGrammar(null, '')).not.toThrow()
+        expect(-> syntax.selectGrammar(null, null)).not.toThrow()
+
   describe ".removeGrammar(grammar)", ->
     it "removes the grammar, so it won't be returned by selectGrammar", ->
       grammar = syntax.selectGrammar('foo.js')

src/app/text-mate-grammar.coffee

@@ -74,11 +74,10 @@ class TextMateGrammar
   getScore: (filePath, contents) ->
     contents = fsUtils.read(filePath) if not contents? and fsUtils.isFileSync(filePath)
 
-
     if syntax.grammarOverrideForPath(filePath) is @scopeName
-      2 + filePath.length
+      2 + (filePath?.length ? 0)
     else if @matchesContents(contents)
-      1 + filePath.length
+      1 + (filePath?.length ? 0)
     else
       @getPathScore(filePath)