Match $ in command regexes as end of line. Don't infinitely loop on substituting zero-width matches

spec/atom/command-interpreter-spec.coffee

@@ -11,25 +11,34 @@ describe "CommandInterpreter", ->
     interpreter = new CommandInterpreter()
 
   describe "addresses", ->
+    beforeEach ->
+      editor.addSelectionForBufferRange([[7,0], [7,11]])
+      editor.addSelectionForBufferRange([[8,0], [8,11]])
+
     describe "a line address", ->
       it "selects the specified line", ->
         interpreter.eval(editor, '4')
+        expect(editor.getSelections().length).toBe 1
         expect(editor.getSelection().getBufferRange()).toEqual [[3, 0], [4, 0]]
 
     describe "0", ->
       it "selects the zero-length string at the start of the file", ->
         interpreter.eval(editor, '0')
+        expect(editor.getSelections().length).toBe 1
         expect(editor.getSelection().getBufferRange()).toEqual [[0,0], [0,0]]
 
         interpreter.eval(editor, '0,1')
+        expect(editor.getSelections().length).toBe 1
         expect(editor.getSelection().getBufferRange()).toEqual [[0,0], [1,0]]
 
     describe "$", ->
       it "selects EOF", ->
         interpreter.eval(editor, '$')
+        expect(editor.getSelections().length).toBe 1
         expect(editor.getSelection().getBufferRange()).toEqual [[12,2], [12,2]]
 
         interpreter.eval(editor, '1,$')
+        expect(editor.getSelections().length).toBe 1
         expect(editor.getSelection().getBufferRange()).toEqual [[0,0], [12,2]]
 
     describe ".", ->
@@ -50,32 +59,38 @@ describe "CommandInterpreter", ->
       it 'selects text matching regex after current selection', ->
         editor.getSelection().setBufferRange([[4,16], [4,20]])
         interpreter.eval(editor, '/pivot/')
+        expect(editor.getSelections().length).toBe 1
         expect(editor.getSelection().getBufferRange()).toEqual [[6,16], [6,21]]
 
       it 'does not require the trailing slash', ->
         editor.getSelection().setBufferRange([[4,16], [4,20]])
         interpreter.eval(editor, '/pivot')
+        expect(editor.getSelections().length).toBe 1
         expect(editor.getSelection().getBufferRange()).toEqual [[6,16], [6,21]]
 
     describe "address range", ->
       describe "when two addresses are specified", ->
         it "selects from the begining of the left address to the end of the right address", ->
           interpreter.eval(editor, '4,7')
+          expect(editor.getSelections().length).toBe 1
           expect(editor.getSelection().getBufferRange()).toEqual [[3, 0], [7, 0]]
 
       describe "when the left address is unspecified", ->
         it "selects from the begining of buffer to the end of the right address", ->
           interpreter.eval(editor, ',7')
+          expect(editor.getSelections().length).toBe 1
           expect(editor.getSelection().getBufferRange()).toEqual [[0, 0], [7, 0]]
 
       describe "when the right address is unspecified", ->
         it "selects from the begining of left address to the end file", ->
           interpreter.eval(editor, '4,')
+          expect(editor.getSelections().length).toBe 1
           expect(editor.getSelection().getBufferRange()).toEqual [[3, 0], [12, 2]]
 
       describe "when the neither address is specified", ->
         it "selects the entire file", ->
           interpreter.eval(editor, ',')
+          expect(editor.getSelections().length).toBe 1
           expect(editor.getSelection().getBufferRange()).toEqual [[0, 0], [12, 2]]
 
   describe "x/regex/", ->
@@ -130,6 +145,14 @@ describe "CommandInterpreter", ->
           expect(buffer.lineForRow(5)).toBe '!!!!!!current!=!items.shift();'
           expect(buffer.lineForRow(6)).toBe '      current < pivot ? left.push(current) : right.push(current);'
 
+      describe "when the regex matches a zero-width string", ->
+        it "does not infinitely loop when looking for the next match", ->
+          interpreter.eval(editor, ',s/$/!!!/g')
+          expect(buffer.lineForRow(0)).toBe 'var quicksort = function () {!!!'
+          expect(buffer.lineForRow(2)).toBe '    if (items.length <= 1) return items;!!!'
+          expect(buffer.lineForRow(6)).toBe '      current < pivot ? left.push(current) : right.push(current);!!!'
+          expect(buffer.lineForRow(12)).toBe '};!!!'
+
   describe ".repeatRelativeAddress()", ->
     it "repeats the last search command if there is one", ->
       interpreter.repeatRelativeAddress(editor) # don't raise an exception

src/atom/command-interpreter/address.coffee

@@ -3,6 +3,8 @@ Command = require 'command-interpreter/command'
 module.exports =
 class Address extends Command
   execute: (editor) ->
-    editor.getSelection().setBufferRange(@getRange(editor))
+    range = @getRange(editor)
+    editor.clearSelections()
+    editor.setSelectionBufferRange(range)
 
   isAddress: -> true

src/atom/command-interpreter/command.coffee

@@ -3,3 +3,6 @@ _ = require 'underscore'
 module.exports =
 class Command
   isAddress: -> false
+
+  regexForPattern: (pattern) ->
+    new RegExp(pattern, 'm')

src/atom/command-interpreter/regex-address.coffee

@@ -6,7 +6,7 @@ class RegexAddress extends Address
   regex: null
 
   constructor: (pattern) ->
-    @regex = new RegExp(pattern)
+    @regex = @regexForPattern(pattern)
 
   getRange: (editor) ->
     selectedRange = editor.getSelection().getBufferRange()

src/atom/command-interpreter/select-all-matches.coffee

@@ -6,7 +6,7 @@ class SelectAllMatches extends Command
   @regex: null
 
   constructor: (pattern) ->
-    @regex = new RegExp(pattern)
+    @regex = @regexForPattern(pattern)
 
   execute: (editor) ->
     rangesToSelect = []

src/atom/command-interpreter/substitution.coffee

@@ -5,7 +5,7 @@ class Substitution extends Command
   global: false
 
   constructor: (@findText, @replaceText, @options) ->
-    @findRegex = new RegExp(@findText)
+    @findRegex = @regexForPattern(@findText)
     @global = 'g' in @options
 
   execute: (editor) ->
@@ -27,7 +27,10 @@ class Substitution extends Command
     buffer.change([startPosition, endPosition], @replaceText)
 
     if @global
-      text = text[(match.index + match[0].length)..]
-      startIndex = matchStartIndex + @replaceText.length
+      offset = if match[0].length then 0 else 1
+      startNextStringFragmentAt = match.index + match[0].length + offset
+      return if startNextStringFragmentAt >= text.length
+      text = text[startNextStringFragmentAt..]
+      startIndex = matchStartIndex + offset + @replaceText.length
       @replace(editor, text, startIndex)