bugdown: Re-enable support for italics in bugdown.

Fixes: #1103.

frontend_tests/node_tests/echo.js

@@ -151,7 +151,9 @@ var bugdown_data = JSON.parse(fs.readFileSync(path.join(__dirname, '../../zerver
     {input: 'This is an !avatar(cordelia@zulip.com) of Cordelia Lear',
      expected: '<p>This is an <img alt="cordelia@zulip.com" class="message_body_gravatar" src="/avatar/cordelia@zulip.com?s=30" title="cordelia@zulip.com"> of Cordelia Lear</p>'},
     {input: 'This is a !gravatar(cordelia@zulip.com) of Cordelia Lear',
-     expected: '<p>This is a <img alt="cordelia@zulip.com" class="message_body_gravatar" src="/avatar/cordelia@zulip.com?s=30" title="cordelia@zulip.com"> of Cordelia Lear</p>'}
+     expected: '<p>This is a <img alt="cordelia@zulip.com" class="message_body_gravatar" src="/avatar/cordelia@zulip.com?s=30" title="cordelia@zulip.com"> of Cordelia Lear</p>'},
+    {input: 'Test *italic*',
+     expected: '<p>Test <em>italic</em></p>'}
   ];
 
   test_cases.forEach(function (test_case) {

static/js/echo.js

@@ -451,11 +451,17 @@ $(function () {
     disable_markdown_regex(marked.Lexer.rules.tables, 'heading');
     disable_markdown_regex(marked.Lexer.rules.tables, 'lheading');
 
-    // Disable __strong__, all <em>
+    // Disable __strong__ (keeping **strong**)
     marked.InlineLexer.rules.zulip.strong = /^\*\*([\s\S]+?)\*\*(?!\*)/;
-    disable_markdown_regex(marked.InlineLexer.rules.zulip, 'em');
+
     // Make sure <del> syntax matches the backend processor
     marked.InlineLexer.rules.zulip.del = /^(?!<\~)\~\~([^~]+)\~\~(?!\~)/;
+
+    // Disable _emphasis_ (keeping *emphasis*)
+    // Text inside ** must start and end with a word character
+    // it need for things like "const char *x = (char *)y"
+    marked.InlineLexer.rules.zulip.em = /^\*(?!\s+)((?:\*\*|[\s\S])+?)((?:[\S]))\*(?!\*)/;
+
     // Disable autolink as (a) it is not used in our backend and (b) it interferes with @mentions
     disable_markdown_regex(marked.InlineLexer.rules.zulip, 'autolink');
 

static/third/marked/lib/marked.js

@@ -742,7 +742,7 @@ InlineLexer.prototype.output = function(src) {
     // em
     if (cap = this.rules.em.exec(src)) {
       src = src.substring(cap[0].length);
-      out += this.renderer.em(this.output(cap[2] || cap[1]));
+      out += this.renderer.em(cap[1] + cap[2]);
       continue;
     }
 

zerver/fixtures/bugdown-data.json

@@ -121,9 +121,21 @@
       "bugdown_matches_marked": true
     },
     {
-      "name": "star_disabled",
+      "name": "emphasis_text",
       "input": "*foo*",
-      "expected_output": "<p>*foo*</p>",
+      "expected_output": "<p><em>foo</em></p>",
+      "bugdown_matches_marked": true
+    },
+    {
+      "name": "emphasis_code",
+      "input": "const char *x = (char *)y",
+      "expected_output": "<p>const char *x = (char *)y</p>",
+      "bugdown_matches_marked": true
+    },
+    {
+      "name": "emphasis_with_space",
+      "input": "A *foo bar* is a *baz quux*",
+      "expected_output": "<p>A <em>foo bar</em> is a <em>baz quux</em></p>",
       "bugdown_matches_marked": true
     },
     {

zerver/lib/bugdown/__init__.py

@@ -1014,6 +1014,13 @@ class Bugdown(markdown.Extension):
             markdown.inlinepatterns.SimpleTagPattern(r'(?<!~)(\~\~)([^~{0}\n]+?)\2(?!~)', 'del'),
             '>strong')
 
+        # Text inside ** must start and end with a word character
+        # it need for things like "const char *x = (char *)y"
+        md.inlinePatterns.add(
+            'emphasis',
+            markdown.inlinepatterns.SimpleTagPattern(r'(\*)(?!\s+)([^\*^\n]+)(?<!\s)\*', 'em'),
+            '>strong')
+
         for k in ('hashheader', 'setextheader', 'olist', 'ulist'):
             del md.parser.blockprocessors[k]