From a73de8c0b5dbdf28c8869587d64c7da60893c331 Mon Sep 17 00:00:00 2001
From: Max Brunsfeld <maxbrunsfeld@gmail.com>
Date: Sat, 23 Sep 2017 00:22:11 -0700
Subject: [PATCH] Avoid spurious updates in autoDecreaseIndentForBufferRow

---
 src/text-editor.coffee  |  5 ++---
 src/tokenized-buffer.js | 13 +++++++------
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/src/text-editor.coffee b/src/text-editor.coffee
index fe9d03a72..2aad26f45 100644
--- a/src/text-editor.coffee
+++ b/src/text-editor.coffee
@@ -3083,8 +3083,7 @@ class TextEditor extends Model
     else
       endColumn = @lineTextForBufferRow(bufferRow).match(/^\s*/)[0].length
     newIndentString = @buildIndentString(newLevel)
-    if newIndentString.length isnt endColumn
-      @buffer.setTextInRange([[bufferRow, 0], [bufferRow, endColumn]], newIndentString)
+    @buffer.setTextInRange([[bufferRow, 0], [bufferRow, endColumn]], newIndentString)
 
   # Extended: Indent rows intersecting selections by one level.
   indentSelectedRows: ->
@@ -3883,7 +3882,7 @@ class TextEditor extends Model
 
   autoDecreaseIndentForBufferRow: (bufferRow) ->
     indentLevel = @tokenizedBuffer.suggestedIndentForEditedBufferRow(bufferRow)
-    @setIndentationForBufferRow(bufferRow, indentLevel)
+    @setIndentationForBufferRow(bufferRow, indentLevel) if indentLevel?
 
   toggleLineCommentForBufferRow: (row) -> @toggleLineCommentsForBufferRows(row, row)
 
diff --git a/src/tokenized-buffer.js b/src/tokenized-buffer.js
index 4cb0e7b4e..b0ee635da 100644
--- a/src/tokenized-buffer.js
+++ b/src/tokenized-buffer.js
@@ -85,7 +85,8 @@ class TokenizedBuffer {
 
   // Get the suggested indentation level for a line in the buffer on which the user is currently
   // typing. This may return a different result from {::suggestedIndentForBufferRow} in order
-  // to avoid unexpected changes in indentation.
+  // to avoid unexpected changes in indentation. It may also return undefined if no change should
+  // be made.
   //
   // * bufferRow - The row {Number}
   //
@@ -93,16 +94,16 @@ class TokenizedBuffer {
   suggestedIndentForEditedBufferRow (bufferRow) {
     const line = this.buffer.lineForRow(bufferRow)
     const currentIndentLevel = this.indentLevelForLine(line)
-    if (currentIndentLevel === 0) return currentIndentLevel
+    if (currentIndentLevel === 0) return
 
     const scopeDescriptor = this.scopeDescriptorForPosition([bufferRow, 0])
     const decreaseIndentRegex = this.decreaseIndentRegexForScopeDescriptor(scopeDescriptor)
-    if (!decreaseIndentRegex) return currentIndentLevel
+    if (!decreaseIndentRegex) return
 
-    if (!decreaseIndentRegex.testSync(line)) return currentIndentLevel
+    if (!decreaseIndentRegex.testSync(line)) return
 
     const precedingRow = this.buffer.previousNonBlankRow(bufferRow)
-    if (precedingRow == null) return currentIndentLevel
+    if (precedingRow == null) return
 
     const precedingLine = this.buffer.lineForRow(precedingRow)
     let desiredIndentLevel = this.indentLevelForLine(precedingLine)
@@ -118,7 +119,7 @@ class TokenizedBuffer {
     }
 
     if (desiredIndentLevel < 0) return 0
-    if (desiredIndentLevel > currentIndentLevel) return currentIndentLevel
+    if (desiredIndentLevel >= currentIndentLevel) return
     return desiredIndentLevel
   }