list match: fix indentation on nested lists

Nested lists use some special rules to allow for inserting another
list after a newline. Unfortunately, do to the current text rule,
the space(s) before the nested list can be added to the text rule
from the first line, rather than the start of the nested list.
This makes further nested items look double-nested, when they
are not.

For 1.0, we should consider changing the text rule to break on
newlines, or change how lookbehinds work (let them "move" text
from previous captures?).

Fixes #48

__tests__/simple-markdown-test.js

@@ -1948,6 +1948,38 @@ describe("simple markdown", function() {
                 ],
                 type: "list",
             }]);
+
+            var parsed = blockParse(
+                " * hi\n" +
+                "    * bye\n" +
+                "    * there\n\n"
+            );
+            validateParse(parsed, [{
+                ordered: false,
+                start: undefined,
+                items: [
+                    [{
+                        content: 'hi\n ', // NOTE(aria): The extra space here is
+                        type: 'text',     //  weird and we should consider fixing
+                    },
+                    {
+                        ordered: false,
+                        start: undefined,
+                        items: [
+                            [{
+                                content: "bye",
+                                type: "text",
+                            }],
+                            [{
+                                content: "there",
+                                type: "text",
+                            }],
+                        ],
+                        type: "list",
+                    }]
+                ],
+                type: "list",
+            }]);
         });
 
         it("should parse loose lists", function() {

package.json

@@ -1,6 +1,6 @@
 {
   "name": "simple-markdown",
-  "version": "0.3.2",
+  "version": "0.3.3",
   "description": "Javascript markdown parsing, made simple",
   "main": "simple-markdown.js",
   "scripts": {

simple-markdown.js

@@ -444,7 +444,7 @@ var LIST_R = new RegExp(
     // lists, where our content might end before we receive two `\n`s
     "|\\s*\n*$)"
 );
-var LIST_LOOKBEHIND_R = /^$|\n *$/;
+var LIST_LOOKBEHIND_R = /(?:^|\n)( *)$/;
 
 var TABLES = (function() {
     // predefine regexes so we don't have to create them inside functions
@@ -725,10 +725,12 @@ var defaultRules = {
             // lists can be inline, because they might be inside another list,
             // in which case we can parse with inline scope, but need to allow
             // nested lists inside this inline scope.
-            var isStartOfLine = LIST_LOOKBEHIND_R.test(prevCapture);
+            var isStartOfLineCapture = LIST_LOOKBEHIND_R.exec(prevCapture);
             var isListBlock = state._list || !state.inline;
 
-            if (isStartOfLine && isListBlock) {
+            if (isStartOfLineCapture && isListBlock) {
+                source = isStartOfLineCapture[1] + source;
+                var res = LIST_R.exec(source);
                 return LIST_R.exec(source);
             } else {
                 return null;