From 36d55c93849950eebd568a798b0976336f3c2fc2 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Mon, 8 Jun 2015 22:56:18 +0200
Subject: [PATCH] =?UTF-8?q?Don=E2=80=99t=20break=20out=20soft=20tabs=20tha?=
 =?UTF-8?q?t=20are=20interrupted=20by=20a=20scope=20boundary?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 spec/tokenized-buffer-spec.coffee | 16 ++++++++++++++++
 src/tokenized-line.coffee         |  7 ++++---
 2 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/spec/tokenized-buffer-spec.coffee b/spec/tokenized-buffer-spec.coffee
index dc57d3fee..23520518a 100644
--- a/spec/tokenized-buffer-spec.coffee
+++ b/spec/tokenized-buffer-spec.coffee
@@ -322,6 +322,22 @@ describe "TokenizedBuffer", ->
         expect(tokens[2].value).toBe " \u030b"
         expect(tokens[2].hasLeadingWhitespace()).toBe false
 
+      it "does not break out soft tabs across a scope boundary", ->
+        waitsForPromise ->
+          atom.packages.activatePackage('language-gfm')
+
+        runs ->
+          tokenizedBuffer.setTabLength(4)
+          tokenizedBuffer.setGrammar(atom.grammars.selectGrammar('.md'))
+          buffer.setText('    <![]()\n    ')
+          fullyTokenize(tokenizedBuffer)
+
+          length = 0
+          for tag in tokenizedBuffer.tokenizedLines[1].tags
+            length += tag if tag > 0
+
+          expect(length).toBe 4
+
   describe "when the buffer contains hard-tabs", ->
     beforeEach ->
       waitsForPromise ->
diff --git a/src/tokenized-line.coffee b/src/tokenized-line.coffee
index b8f7226c8..bd871fc4f 100644
--- a/src/tokenized-line.coffee
+++ b/src/tokenized-line.coffee
@@ -102,10 +102,11 @@ class TokenizedLine
           substringEnd += 1
         else
           if (screenColumn + 1) % @tabLength is 0
-            @specialTokens[tokenIndex] = SoftTab
             suffix = @tags[tokenIndex] - @tabLength
-            @tags.splice(tokenIndex, 1, @tabLength)
-            @tags.splice(tokenIndex + 1, 0, suffix) if suffix > 0
+            if suffix >= 0
+              @specialTokens[tokenIndex] = SoftTab
+              @tags.splice(tokenIndex, 1, @tabLength)
+              @tags.splice(tokenIndex + 1, 0, suffix) if suffix > 0
 
           if @invisibles?.space
             if substringEnd > substringStart