Better inline code escaping (#533)

This aims to escape code in a more expected fashion.   This handles
when backticks are escaped and when the escapes before backticks are
escaped.

5 files changed, 42 insertions, 10 deletions

diff --git a/markdown/inlinepatterns.py b/markdown/inlinepatterns.py
index 67bc2a8..37c9afa 100644
--- a/markdown/inlinepatterns.py
+++ b/markdown/inlinepatterns.py
@@ -103,7 +103,7 @@ BRK = (
 NOIMG = r'(?<!\!)'
 
 # `e=f()` or ``e=f("`")``
-BACKTICK_RE = r'(?<!\\)(`+)(.+?)(?<!`)\2(?!`)'
+BACKTICK_RE = r'(?:(?<!\\)((?:\\{2})+)(?=`+)|(?<!\\)(`+)(.+?)(?<!`)\3(?!`))'
 
 # \<
 ESCAPE_RE = r'\\(.)'
@@ -302,12 +302,16 @@ class BacktickPattern(Pattern):
     """ Return a `<code>` element containing the matching text. """
     def __init__(self, pattern):
         Pattern.__init__(self, pattern)
-        self.tag = "code"
+        self.ESCAPED_BSLASH = '%s%s%s' % (util.STX, ord('\\'), util.ETX)
+        self.tag = 'code'
 
     def handleMatch(self, m):
-        el = util.etree.Element(self.tag)
-        el.text = util.AtomicString(m.group(3).strip())
-        return el
+        if m.group(4):
+            el = util.etree.Element(self.tag)
+            el.text = util.AtomicString(m.group(4).strip())
+            return el
+        else:
+            return m.group(2).replace('\\\\', self.ESCAPED_BSLASH)
 
 
 class DoubleTagPattern(SimpleTagPattern):
diff --git a/tests/extensions/extra/tables.html b/tests/extensions/extra/tables.html
index b81582c..2418c98 100644
--- a/tests/extensions/extra/tables.html
+++ b/tests/extensions/extra/tables.html
@@ -356,4 +356,23 @@ Content Cell | Content Cell
 <p>| Column1   | Column2 |
 | ------- || ------- |
 | row1      | row1    |
-| row2      | row2    |</p>
\ No newline at end of file
+| row2      | row2    |</p>
+<p>Test escaped code in Table</p>
+<table>
+<thead>
+<tr>
+<th>Should not be code</th>
+<th>Should be code</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>`Not code`</td>
+<td>\<code>code</code></td>
+</tr>
+<tr>
+<td>\`Not code\`</td>
+<td>\\<code>code</code></td>
+</tr>
+</tbody>
+</table>
\ No newline at end of file
diff --git a/tests/extensions/extra/tables.txt b/tests/extensions/extra/tables.txt
index d5bd6ea..d766224 100644
--- a/tests/extensions/extra/tables.txt
+++ b/tests/extensions/extra/tables.txt
@@ -121,3 +121,10 @@ Escaped pipes in format row should not be a table
 | ------- \|| ------- |
 | row1      | row1    |
 | row2      | row2    |
+
+Test escaped code in Table
+
+Should not be code | Should be code
+------------------ | --------------
+\`Not code\`       | \\`code`
+\\\`Not code\\\`   | \\\\`code`
diff --git a/tests/misc/backtick-escape.html b/tests/misc/backtick-escape.html
index 07f5115..da30541 100644
--- a/tests/misc/backtick-escape.html
+++ b/tests/misc/backtick-escape.html
@@ -1,3 +1,4 @@
-<p>\`This should not be in code.\`
-`This also should not be in code.`
+<p>`This should not be in code.`
+\<code>This should be in code.\\</code>
+\`This should not be in code.\`
 `And finally this should not be in code.`</p>
\ No newline at end of file
diff --git a/tests/misc/backtick-escape.txt b/tests/misc/backtick-escape.txt
index b4d80b2..c019463 100644
--- a/tests/misc/backtick-escape.txt
+++ b/tests/misc/backtick-escape.txt
@@ -1,3 +1,4 @@
-\\`This should not be in code.\\`
-\`This also should not be in code.\`
+\`This should not be in code.\`
+\\`This should be in code.\\`
+\\\`This should not be in code.\\\`
 \`And finally this should not be in code.`