[FIX] match all occurrences of static/attach

If a markup element contains more than one {static} or {attach} value,
only the last one was replaced.

Simplify the regex to match every occurrence

Fixes #3419

pelican/contents.py

@@ -372,9 +372,7 @@ def _find_path(path: str) -> Optional[Content]:
     def _get_intrasite_link_regex(self) -> re.Pattern:
         intrasite_link_regex = self.settings["INTRASITE_LINK_REGEX"]
         regex = rf"""
-            (?P<markup><[^\>]+  # match tag with all url-value attributes
-                (?:href|src|poster|data|cite|formaction|action|content)\s*=\s*)
-
+            (?P<markup>(?:href|src|poster|data|cite|formaction|action|content)\s*=\s*)
             (?P<quote>["\'])      # require value to be quoted
             (?P<path>{intrasite_link_regex}(?P<value>.*?))  # the url value
             (?P=quote)"""

pelican/tests/test_contents.py

@@ -547,6 +547,13 @@ def test_intrasite_link_absolute(self):
             content, '<img src="http://static.cool.site/images/poster.jpg"/>'
         )
 
+        # Image with two links
+        args["content"] = '<img src="{static}/images/placeholder.jpg" data-src="{static}/images/poster.jpg"/>'
+        content = Page(**args).get_content("http://cool.site")
+        self.assertEqual(
+            content, '<img src="http://static.cool.site/images/placeholder.jpg" data-src="http://static.cool.site/images/poster.jpg"/>'
+        )
+
         # Image link will go to static
         args["content"] = '<meta content="{static}/images/poster.jpg"/>'
         content = Page(**args).get_content("http://cool.site")