bugdown: Allow block-level block quotes

It is triggered by specifying the "language" of a code block to
"quote" or "quoted":
    Hamlet said:
    ~~~ quote
    To be or **not** to be.

    That is the question
    ~~~

(imported from commit 847a0602e335e9f2955e32d9955adf8ac8de068c)

zerver/lib/bugdown/fenced_code.py

@@ -107,6 +107,15 @@ class FencedBlockPreprocessor(markdown.preprocessors.Preprocessor):
         if m.group('lang'):
             langclass = LANG_TAG % m.group('lang')
 
+            if m.group('lang') in ('quote', 'quoted'):
+                paragraphs = m.group('code').split("\n\n")
+                quoted_paragraphs = []
+                for paragraph in paragraphs:
+                    lines = paragraph.split("\n")
+                    quoted_paragraphs.append("\n".join("> " + line for line in lines if line != ''))
+                replacement = "\n\n".join(quoted_paragraphs)
+                return '%s\n%s\n%s'% (text[:m.start()], replacement, text[m.end():])
+
         # If config is not empty, then the codehighlite extension
         # is enabled, so we call it to highlite the code
         if self.codehilite_conf:

zerver/tests.py

@@ -2329,6 +2329,49 @@ def foobar(self):
 </pre></div>"""
         self.common_bugdown_test(fenced_code, expected_convert)
 
+    def test_fenced_quote(self):
+        fenced_quote = \
+"""Hamlet said:
+~~~ quote
+To be or **not** to be.
+
+That is the question
+~~~"""
+
+        expected_convert = \
+"""<p>Hamlet said:</p>
+<blockquote>
+<p>To be or <strong>not</strong> to be.</p>
+<p>That is the question</p>
+</blockquote>"""
+        self.common_bugdown_test(fenced_quote, expected_convert)
+
+    def test_fenced_nested_quote(self):
+        fenced_quote = \
+"""Hamlet said:
+~~~ quote
+Polonius said:
+> This above all: to thine ownself be true,
+And it must follow, as the night the day,
+Thou canst not then be false to any man.
+
+What good advice!
+~~~"""
+
+        expected_convert = \
+"""<p>Hamlet said:</p>
+<blockquote>
+<p>Polonius said:</p>
+<blockquote>
+<p>This above all: to thine ownself be true,<br>
+And it must follow, as the night the day,<br>
+Thou canst not then be false to any man.</p>
+</blockquote>
+<p>What good advice!</p>
+</blockquote>"""
+
+        self.common_bugdown_test(fenced_quote, expected_convert)
+
     def test_dangerous_block(self):
         fenced_code = u'xxxxxx xxxxx xxxxxxxx xxxx. x xxxx xxxxxxxxxx:\n\n```\
 "xxxx xxxx\\xxxxx\\xxxxxx"```\n\nxxx xxxx xxxxx:```xx.xxxxxxx(x\'^xxxx$\'\