feat(splitAdjacentBlockquotes): add option to split adjacent blockquote blocks

With this option enabled, this:

```md
> some text

> some other text
```

witll result in:

```html
<blockquote>
    <p>some text</p>
</blockquote>
<blockquote>
    <p>some other text</p>
</blockquote>
```

This is the default behavior of GFM.

Closes #477

README.md

@@ -366,6 +366,8 @@ var defaultOptions = showdown.getDefaultOptions();
  * **metadata**: (boolean) [default false] Enable support for document metadata (defined at the top of the document
    between `«««` and `»»»` or between `---` and `---`).  (since v.1.8.5)
 
+ * **splitAdjacentBlockquotes**: (boolean) [default false] Split adjacent blockquote blocks.(since v.1.8.6)
+
 **NOTE**: Please note that until **version 1.6.0**, all of these options are ***DISABLED*** by default in the cli tool.
 
 

src/options.js

@@ -160,6 +160,11 @@ function getDefaultOpts (simple) {
       defaultValue: false,
       description: 'Enable support for document metadata (defined at the top of the document between `«««` and `»»»` or between `---` and `---`).',
       type: 'boolean'
+    },
+    splitAdjacentBlockquotes: {
+      defaultValue: false,
+      description: 'Split adjacent blockquote blocks',
+      type: 'boolean'
     }
   };
   if (simple === false) {

src/showdown.js

@@ -33,7 +33,8 @@ var showdown = {},
         ghCompatibleHeaderId:                 true,
         ghMentions:                           true,
         backslashEscapesHTMLTags:             true,
-        emoji:                                true
+        emoji:                                true,
+        splitAdjacentBlockquotes:             true
       },
       original: {
         noHeaderId:                           true,

src/subParsers/makehtml/blockQuotes.js

@@ -3,12 +3,19 @@ showdown.subParser('makehtml.blockQuotes', function (text, options, globals) {
 
   text = globals.converter._dispatch('makehtml.blockQuotes.before', text, options, globals);
 
-  text = text.replace(/((^ {0,3}>[ \t]?.+\n(.+\n)*\n*)+)/gm, function (wholeMatch, m1) {
-    var bq = m1;
+  // add a couple extra lines after the text and endtext mark
+  text = text + '\n\n';
 
+  var rgx = /(^ {0,3}>[ \t]?.+\n(.+\n)*\n*)+/gm;
+
+  if (options.splitAdjacentBlockquotes) {
+    rgx = /^ {0,3}>[\s\S]*?(?:\n\n)/gm;
+  }
+
+  text = text.replace(rgx, function (bq) {
     // attacklab: hack around Konqueror 3.5.4 bug:
     // "----------bug".replace(/^-/g,"") == "bug"
-    bq = bq.replace(/^[ \t]*>[ \t]?/gm, '¨0'); // trim one level of quoting
+    bq = bq.replace(/^[ \t]*>[ \t]?/gm, ''); // trim one level of quoting
 
     // attacklab: clean up hack
     bq = bq.replace(/¨0/g, '');

test/features/splitAdjacentBlockquotes/basic.html

@@ -0,0 +1,8 @@
+<blockquote>
+    <h1 id="blockquote1">Block quote  1</h1>
+    <p>This is my first block quote.</p>
+</blockquote>
+<blockquote>
+    <h1 id="blockquote2">Block quote 2</h1>
+    <p>This is my second block quote.</p>
+</blockquote>

test/features/splitAdjacentBlockquotes/basic.md

@@ -0,0 +1,7 @@
+> # Block quote  1
+>
+> This is my first block quote.
+
+> # Block quote 2
+>
+> This is my second block quote.

test/features/splitAdjacentBlockquotes/multiline-paragraph.html

@@ -0,0 +1,6 @@
+<blockquote>
+<p>This is my second block quote
+yeah
+everythong is ok.</p>
+</blockquote>
+<p>This is not a blockquote</p>

test/features/splitAdjacentBlockquotes/multiline-paragraph.md

@@ -0,0 +1,5 @@
+> This is my second block quote
+yeah
+everythong is ok.
+
+This is not a blockquote

test/node/testsuite.features.js

@@ -16,7 +16,8 @@ var bootstrap = require('../bootstrap.js'),
     literalMidWordUnderscoresSuite = bootstrap.getTestSuite('test/features/literalMidWordUnderscores/'),
     literalMidWordAsterisksSuite = bootstrap.getTestSuite('test/features/literalMidWordAsterisks/'),
     completeHTMLOutputSuite = bootstrap.getTestSuite('test/features/completeHTMLOutput/'),
-    metadataSuite = bootstrap.getTestSuite('test/features/metadata/');
+    metadataSuite = bootstrap.getTestSuite('test/features/metadata/'),
+    splitAdjacentBlockquotesSuite = bootstrap.getTestSuite('test/features/splitAdjacentBlockquotes/');
 
 describe('makeHtml() features testsuite', function () {
   'use strict';
@@ -264,4 +265,15 @@ describe('makeHtml() features testsuite', function () {
       it(suite[i].name.replace(/-/g, ' '), assertion(suite[i], converter));
     }
   });
+
+  /** test metadata option **/
+  describe('splitAdjacentBlockquotes option', function () {
+    var converter,
+        suite = splitAdjacentBlockquotesSuite;
+
+    for (var i = 0; i < suite.length; ++i) {
+      converter = new showdown.Converter({splitAdjacentBlockquotes: true});
+      it(suite[i].name.replace(/-/g, ' '), assertion(suite[i], converter));
+    }
+  });
 });