From 20c01cf12fab27c26d1bb0b66c9dca5904cfa148 Mon Sep 17 00:00:00 2001
From: Evilham <cvs@evilham.com>
Date: Sun, 10 Oct 2021 20:45:50 +0200
Subject: [PATCH 1/5] Support newer mistune versions in addition to older ones

It looks like lepture has been busy and mistune 2.0.0 is about to be
released, there is already some software that depends on its alpha/rc
versions and rather than backporting that, it makes more sense to
prepare Lektor to be compatible with the newer version.

This patch aims to introduce minimal changes to achieve that while
keeping compatibility with mistune 0.8.X.
---
 lektor/markdown.py |   68 +++++++++++++++++++++++++++++++++++------------------
 setup.cfg          |    2 -
 2 files changed, 46 insertions(+), 24 deletions(-)

--- a/lektor/markdown.py
+++ b/lektor/markdown.py
@@ -14,30 +14,50 @@ _markdown_cache = threading.local()
 def escape(text: str) -> str:
     return mistune.escape(text, quote=True)
 
+_old_mistune = int(mistune.__version__.split(".", maxsplit=1)[0]) < 2
 
-class ImprovedRenderer(mistune.Renderer):
-    def link(self, link, title, text):
-        if self.record is not None:
-            url = url_parse(link)
-            if not url.scheme:
-                link = self.record.url_to("!" + link, base_url=get_ctx().base_url)
-        link = escape(link)
-        if not title:
-            return '<a href="%s">%s</a>' % (link, text)
-        title = escape(title)
-        return '<a href="%s" title="%s">%s</a>' % (link, title, text)
+if _old_mistune:
 
-    def image(self, src, title, text):
-        if self.record is not None:
-            url = url_parse(src)
-            if not url.scheme:
-                src = self.record.url_to("!" + src, base_url=get_ctx().base_url)
-        src = escape(src)
-        text = escape(text)
-        if title:
-            title = escape(title)
-            return '<img src="%s" alt="%s" title="%s">' % (src, text, title)
-        return '<img src="%s" alt="%s">' % (src, text)
+    class ImprovedRenderer(mistune.Renderer):
+        def link(self, link, title, text):
+            return _render_link(link, text, title, record=self.record)
+
+        def image(self, src, title, text):
+            return _render_image(src, text, title, record=self.record)
+
+else:
+
+    class ImprovedRenderer(mistune.HTMLRenderer):
+        def link(self, link, text=None, title=None):
+            return _render_link(link, text, title, record=self.record)
+
+        def image(self, src, alt=None, title=None):
+            return _render_image(src, alt, title, record=self.record)
+
+
+def _render_link(link, text=None, title=None, record=None):
+    if record is not None:
+        url = url_parse(link)
+        if not url.scheme:
+            link = record.url_to("!" + link, base_url=get_ctx().base_url)
+    link = escape(link)
+    if not title:
+        return '<a href="%s">%s</a>' % (link, text)
+    title = escape(title)
+    return '<a href="%s" title="%s">%s</a>' % (link, title, text)
+
+
+def _render_image(src, alt="", title=None, record=None):
+    if record is not None:
+        url = url_parse(src)
+        if not url.scheme:
+            src = record.url_to("!" + src, base_url=get_ctx().base_url)
+    src = escape(src)
+    alt = escape(alt)
+    if title:
+        title = escape(title)
+        return '<img src="%s" alt="%s" title="%s">' % (src, alt, title)
+    return '<img src="%s" alt="%s">' % (src, alt)
 
 
 class MarkdownConfig:
@@ -59,7 +79,9 @@ def make_markdown(env):
     env.plugin_controller.emit("markdown-config", config=cfg)
     renderer = cfg.make_renderer()
     env.plugin_controller.emit("markdown-lexer-config", config=cfg, renderer=renderer)
-    return mistune.Markdown(renderer, **cfg.options)
+    if _old_mistune:
+        return mistune.Markdown(renderer, **cfg.options)
+    return mistune.create_markdown(renderer=renderer, **cfg.options)
 
 
 def markdown_to_html(text, record=None):
--- a/setup.cfg
+++ b/setup.cfg
@@ -37,7 +37,7 @@ install_requires =
 	Flask
 	inifile>=0.4.1
 	Jinja2>=3.0
-	mistune>=0.7.0,<2
+	mistune>=0.7.0,<3
 	pip
 	python-slugify
 	requests[security]