From 7176b04a2e1273de72aeaeb72241db808b74d60a Mon Sep 17 00:00:00 2001
From: agu2347 <94227848+agu2347@users.noreply.github.com>
Date: Tue, 25 Aug 2026 15:54:44 +0530
Subject: [PATCH] Escape `"` in image titles (#586)

image() in src/mdformat/renderer/_context.py rendered node.attrs['title']
directly into the parenthesized `(uri "title")` form without escaping
embedded double quotes, unlike link() a few lines below which already
does `title.replace('"', '\\\\"')`. An unescaped quote in an image title
terminates the title early, producing malformed Markdown, and made
mdformat.text() non-idempotent on such input (a second format pass
reparsed the corrupted output differently, even escaping the image
brackets themselves).

Mirror link()'s escaping in image() so titles round-trip correctly.

Adds a `link and image titles with embedded quotes` case to
tests/data/default_style.md covering both link and image titles.
---
 src/mdformat/renderer/_context.py |  2 ++
 tests/data/default_style.md       | 11 +++++++++++
 2 files changed, 13 insertions(+)

diff --git a/src/mdformat/renderer/_context.py b/src/mdformat/renderer/_context.py
index 238dd07d..73150c3d 100644
--- a/src/mdformat/renderer/_context.py
+++ b/src/mdformat/renderer/_context.py
@@ -218,6 +218,8 @@ def image(node: RenderTreeNode, context: RenderContext) -> str:
     uri = maybe_add_link_brackets(uri)
     title = node.attrs.get("title")
     if title is not None:
+        assert isinstance(title, str)
+        title = title.replace('"', '\\"')
         return f'![{description}]({uri} "{title}")'
     return f"![{description}]({uri})"
 
diff --git a/tests/data/default_style.md b/tests/data/default_style.md
index 7f1d4538..eed8b3ed 100644
--- a/tests/data/default_style.md
+++ b/tests/data/default_style.md
@@ -130,6 +130,17 @@ references:
 [ref2]: link3 "title"
 .
 
+link and image titles with embedded quotes
+.
+[text](link1 "a \"quoted\" title")
+
+![text](img.png "a \"quoted\" title")
+.
+[text](link1 "a \"quoted\" title")
+
+![text](img.png "a \"quoted\" title")
+.
+
 thematic breaks
 .
 something something