From 052e3cc8eb55200628c23dba64789724fd50f5fd Mon Sep 17 00:00:00 2001
From: Hao-kang Den <haokang.den@gmail.com>
Date: Wed, 13 Mar 2013 21:43:29 +0800
Subject: [PATCH 1/2] found a linear shift of lineno, dirty patch for now

It seems that js -> coffee line mapping has a linear shifting.
Dirty patch by applying linear correction.
Dumb, but maybe a hint.
---
 lib/coffee-script/coffee-script.js |  5 ++++-
 src/coffee-script.coffee           | 17 +++++++++--------
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/lib/coffee-script/coffee-script.js b/lib/coffee-script/coffee-script.js
index c29ba622..c238a3f2 100644
--- a/lib/coffee-script/coffee-script.js
+++ b/lib/coffee-script/coffee-script.js
@@ -233,7 +233,10 @@
         var answer, sourceMap;
         sourceMap = mainModule._sourceMaps[filename];
         if (sourceMap) {
-          answer = sourceMap.getSourcePosition([line, column]);
+          answer = sourceMap.getSourcePosition([line - 1, column]);
+        }
+        if (answer) {
+          answer[0] += 1;
         }
         return answer;
       };
diff --git a/src/coffee-script.coffee b/src/coffee-script.coffee
index 7592039d..550603c5 100644
--- a/src/coffee-script.coffee
+++ b/src/coffee-script.coffee
@@ -193,18 +193,12 @@ parser.yy.parseError = (message, {token}) ->
 # sourceMap, so we must monkey-patch Error to display CoffeeScript source
 # positions.
 
-# Ideally, this would happen in a way that is scalable to multiple compile-to-
-# JS languages trying to do the same thing in the same NodeJS process. We can
-# implement it as if there were an API, and then patch in support for that
-# API. The following maybe should be in its own npm module that multiple
-# compilers can include.
-
 patched = false
 patchStackTrace = ->
   return if patched
   patched = true
   mainModule = require.main
-  # Map of filenames -> functions that return a sourceMap string.
+  # Map of filenames -> sourceMap object.
   mainModule._sourceMaps = {}
 
   # (Assigning to a property of the Module object in the normal module cache is
@@ -216,7 +210,14 @@ patchStackTrace = ->
 
     getSourceMapping = (filename, line, column) ->
       sourceMap = mainModule._sourceMaps[filename]
-      answer = sourceMap.getSourcePosition [line, column] if sourceMap
+      answer = sourceMap.getSourcePosition [line - 1, column] if sourceMap
+      if answer
+        answer[0] += 1
+        # # un-comment to dirty patch the column number, not very accurate
+        # if answer[1] > 3
+        #   answer[1] -= 3
+        # else
+        #   answer[1] = 0
       answer
 
     frames = for frame in stack

From d4254a40a9b809d93e3dc7a8d950ce4f25152b3a Mon Sep 17 00:00:00 2001
From: Hao-kang Den <haokang.den@gmail.com>
Date: Thu, 14 Mar 2013 08:23:27 +0800
Subject: [PATCH 2/2] Apply modifications by @jwalton

---
 lib/coffee-script/coffee-script.js |  7 ++++---
 src/coffee-script.coffee           | 11 ++---------
 2 files changed, 6 insertions(+), 12 deletions(-)

diff --git a/lib/coffee-script/coffee-script.js b/lib/coffee-script/coffee-script.js
index c238a3f2..2b5bc335 100644
--- a/lib/coffee-script/coffee-script.js
+++ b/lib/coffee-script/coffee-script.js
@@ -233,12 +233,13 @@
         var answer, sourceMap;
         sourceMap = mainModule._sourceMaps[filename];
         if (sourceMap) {
-          answer = sourceMap.getSourcePosition([line - 1, column]);
+          answer = sourceMap.getSourcePosition([line - 1, column - 1]);
         }
         if (answer) {
-          answer[0] += 1;
+          return [answer[0] + 1, answer[1] + 1];
+        } else {
+          return null;
         }
-        return answer;
       };
       frames = (function() {
         var _j, _len1, _results;
diff --git a/src/coffee-script.coffee b/src/coffee-script.coffee
index 550603c5..e806bf46 100644
--- a/src/coffee-script.coffee
+++ b/src/coffee-script.coffee
@@ -210,15 +210,8 @@ patchStackTrace = ->
 
     getSourceMapping = (filename, line, column) ->
       sourceMap = mainModule._sourceMaps[filename]
-      answer = sourceMap.getSourcePosition [line - 1, column] if sourceMap
-      if answer
-        answer[0] += 1
-        # # un-comment to dirty patch the column number, not very accurate
-        # if answer[1] > 3
-        #   answer[1] -= 3
-        # else
-        #   answer[1] = 0
-      answer
+      answer = sourceMap.getSourcePosition [line-1, column-1] if sourceMap
+      if answer then [answer[0]+1, answer[1]+1] else null
 
     frames = for frame in stack
       break if frame.getFunction() is exports.run