Preserve queries and fragments when rewriting Markdown file links

CHANGES.md

@@ -2,6 +2,7 @@
 
 ## python-markdown2 2.5.6 (not yet released)
 
+- [pull #746] Preserve query strings and fragments in `markdown-file-links` conversions, including reference-link targets.
 - [pull #739] Fix `header-ids` extra putting sanitized HTML into header ids in safe mode, which allowed attribute injection (#649)
 - [pull #732] Fix excessive CPU use in the inline HTML tokenizer on repeated unclosed tag fragments (#707)
 - [pull #736] Clarify how to enable file variables in the Python API and command-line help (#269, #365).

lib/markdown2.py

@@ -3928,7 +3928,8 @@ class _MarkdownFileLinksExtraOpts(_LinkProcessorExtraOpts, total=False):
 
 class MarkdownFileLinks(LinkProcessor):
     '''
-    Replace links to `.md` files with `.html` links
+    Replace links to `.md` files with `.html` links, preserving query strings
+    and fragments.
     '''
 
     name = 'markdown-file-links'
@@ -3942,24 +3943,37 @@ def __init__(self, md: Markdown, options: Optional[dict]):
 
     def parse_inline_anchor_or_image(self, text: str, _link_text: str, start_idx: int):
         result = super().parse_inline_anchor_or_image(text, _link_text, start_idx)
-        if not result or not result[1] or not result[1].endswith('.md'):
-            # return None for invalid markup, or links that don't end with '.md'
-            # so that we don't touch them, and other extras can process them freely
+        if not result or not result[1]:
+            return
+        url = self._convert_url(result[1])
+        if url == result[1]:
+            # Leave other links available for processing by other extras.
             return
-        url = result[1].removesuffix('.md') + '.html'
         return result[0], url, *result[2:]
 
+    @staticmethod
+    def _convert_url(url: str) -> str:
+        # Split before the suffix, keeping its spelling and empty delimiters.
+        path = re.split(r'[?#]', url, maxsplit=1)[0]
+        if path.endswith('.md'):
+            return path.removesuffix('.md') + '.html' + url[len(path):]
+        return url
+
     def run(self, text: str):
         if Stage.LINKS > self.md.order > Stage.LINK_DEFS and self.options.get('link_defs', True):
             # running just after link defs have been stripped
             for key, url in self.md.urls.items():
-                if url.endswith('.md'):
-                    self.md.urls[key] = url.removesuffix('.md') + '.html'
+                path = re.split(r'[?#]', url, maxsplit=1)[0]
+                if path.endswith('.md'):
+                    self.md.urls[key] = self._convert_url(url)
 
         return super().run(text)
 
     def test(self, text: str):
-        return super().test(text) and '.md' in text
+        # Link definitions have already been removed from text at this stage.
+        return super().test(text) and (
+            '.md' in text or self.md.stage == Stage.LINK_DEFS
+        )
 
 
 class Mermaid(FencedCodeBlocks):

test/tm-cases/markdown_file_links_inline_suffixes.html

@@ -0,0 +1,35 @@
+<p><a href="guide.html">doc</a></p>
+
+<p><a href="guide.html#install">doc</a></p>
+
+<p><a href="guide.html?view=print">doc</a></p>
+
+<p><a href="guide.html?view=print#install">doc</a></p>
+
+<p><a href="guide.html#part?view=print">doc</a></p>
+
+<p><a href="guide.html?">doc</a></p>
+
+<p><a href="guide.html#">doc</a></p>
+
+<p><a href="guide.html?#">doc</a></p>
+
+<p><a href="./guide.html?next=other.md#part.md">doc</a></p>
+
+<p><a href="https://example.com/guide.html#install">doc</a></p>
+
+<p><a href="//example.com/guide.html?view=print">doc</a></p>
+
+<p><a href="#part.md">doc</a></p>
+
+<p><a href="?download=guide.md">doc</a></p>
+
+<p><a href="guide.html#part.md">doc</a></p>
+
+<p><a href="guide.html?next=guide.md">doc</a></p>
+
+<p><a href="guide.md/child">doc</a></p>
+
+<p><a href="guide.md.bak#part">doc</a></p>
+
+<p><img src="guide.md#install" alt="image" /></p>

test/tm-cases/markdown_file_links_inline_suffixes.opts

@@ -0,0 +1 @@
+{'extras': ['markdown-file-links']}

test/tm-cases/markdown_file_links_inline_suffixes.text

@@ -0,0 +1,35 @@
+[doc](guide.md)
+
+[doc](guide.md#install)
+
+[doc](guide.md?view=print)
+
+[doc](guide.md?view=print#install)
+
+[doc](guide.md#part?view=print)
+
+[doc](guide.md?)
+
+[doc](guide.md#)
+
+[doc](guide.md?#)
+
+[doc](./guide.md?next=other.md#part.md)
+
+[doc](https://example.com/guide.md#install)
+
+[doc](//example.com/guide.md?view=print)
+
+[doc](#part.md)
+
+[doc](?download=guide.md)
+
+[doc](guide.html#part.md)
+
+[doc](guide.html?next=guide.md)
+
+[doc](guide.md/child)
+
+[doc](guide.md.bak#part)
+
+![image](guide.md#install)

test/tm-cases/markdown_file_links_no_linkdefs.html

@@ -1 +1,3 @@
 <p><a href="./something.md">This is a reference to a markdown file link</a> but link definition swapping is disabled</p>
+
+<p><a href="guide.html#install">inline</a> and <a href="guide.md#install">reference</a></p>

test/tm-cases/markdown_file_links_no_linkdefs.text

@@ -1,4 +1,7 @@
 [This is a reference to a markdown file link][] but link definition swapping is disabled
 
 
+[inline](guide.md#install) and [reference][suffix-ref]
+
 [This is a reference to a markdown file link]: ./something.md
+[suffix-ref]: guide.md#install

test/tm-cases/markdown_file_links_reference_suffixes.html

@@ -0,0 +1,33 @@
+<p><a href="guide.html">doc</a></p>
+
+<p><a href="guide.html#install">doc</a></p>
+
+<p><a href="guide.html?view=print">doc</a></p>
+
+<p><a href="guide.html?view=print#install">doc</a></p>
+
+<p><a href="guide.html#part?view=print">doc</a></p>
+
+<p><a href="guide.html?">doc</a></p>
+
+<p><a href="guide.html#">doc</a></p>
+
+<p><a href="guide.html?#">doc</a></p>
+
+<p><a href="./guide.html?next=other.md#part.md">doc</a></p>
+
+<p><a href="https://example.com/guide.html#install">doc</a></p>
+
+<p><a href="//example.com/guide.html?view=print">doc</a></p>
+
+<p><a href="#part.md">doc</a></p>
+
+<p><a href="?download=guide.md">doc</a></p>
+
+<p><a href="guide.html#part.md">doc</a></p>
+
+<p><a href="guide.html?next=guide.md">doc</a></p>
+
+<p><a href="guide.md/child">doc</a></p>
+
+<p><a href="guide.md.bak#part">doc</a></p>

test/tm-cases/markdown_file_links_reference_suffixes.opts

@@ -0,0 +1 @@
+{'extras': ['markdown-file-links']}

test/tm-cases/markdown_file_links_reference_suffixes.text

@@ -0,0 +1,51 @@
+[doc][suffix-1]
+
+[doc][suffix-2]
+
+[doc][suffix-3]
+
+[doc][suffix-4]
+
+[doc][suffix-5]
+
+[doc][suffix-6]
+
+[doc][suffix-7]
+
+[doc][suffix-8]
+
+[doc][suffix-9]
+
+[doc][suffix-10]
+
+[doc][suffix-11]
+
+[doc][suffix-12]
+
+[doc][suffix-13]
+
+[doc][suffix-14]
+
+[doc][suffix-15]
+
+[doc][suffix-16]
+
+[doc][suffix-17]
+
+[suffix-1]: guide.md
+[suffix-2]: guide.md#install
+[suffix-3]: guide.md?view=print
+[suffix-4]: guide.md?view=print#install
+[suffix-5]: guide.md#part?view=print
+[suffix-6]: guide.md?
+[suffix-7]: guide.md#
+[suffix-8]: guide.md?#
+[suffix-9]: ./guide.md?next=other.md#part.md
+[suffix-10]: https://example.com/guide.md#install
+[suffix-11]: //example.com/guide.md?view=print
+[suffix-12]: #part.md
+[suffix-13]: ?download=guide.md
+[suffix-14]: guide.html#part.md
+[suffix-15]: guide.html?next=guide.md
+[suffix-16]: guide.md/child
+[suffix-17]: guide.md.bak#part