Fix #7019: gettext: Absolute path used in message catalogs

CHANGES

@@ -47,6 +47,7 @@ Bugs fixed
 * #6559: Wrong node-ids are generated in glossary directive
 * #6986: apidoc: misdetects module name for .so file inside module
 * #6999: napoleon: fails to parse tilde in :exc: role
+* #7019: gettext: Absolute path used in message catalogs
 
 Testing
 --------

sphinx/builders/gettext.py

@@ -30,7 +30,7 @@ from sphinx.util import split_index_msg, logging, status_iterator
 from sphinx.util.console import bold  # type: ignore
 from sphinx.util.i18n import CatalogInfo, docname_to_domain
 from sphinx.util.nodes import extract_messages, traverse_translatable_index
-from sphinx.util.osutil import ensuredir, canon_path
+from sphinx.util.osutil import ensuredir, canon_path, relpath
 from sphinx.util.tags import Tags
 from sphinx.util.template import SphinxRenderer
 
@@ -108,7 +108,8 @@ class MsgOrigin:
 
 
 class GettextRenderer(SphinxRenderer):
-    def __init__(self, template_path: str = None) -> None:
+    def __init__(self, template_path: str = None, outdir: str = None) -> None:
+        self.outdir = outdir
         if template_path is None:
             template_path = path.join(package_dir, 'templates', 'gettext')
         super().__init__(template_path)
@@ -122,6 +123,13 @@ class GettextRenderer(SphinxRenderer):
         self.env.filters['e'] = escape
         self.env.filters['escape'] = escape
 
+    def render(self, filename: str, context: Dict) -> str:
+        def _relpath(s: str) -> str:
+            return canon_path(relpath(s, self.outdir))
+
+        context['relpath'] = _relpath
+        return super().render(filename, context)
+
 
 class I18nTags(Tags):
     """Dummy tags module for I18nBuilder.
@@ -297,7 +305,7 @@ class MessageCatalogBuilder(I18nBuilder):
             ensuredir(path.join(self.outdir, path.dirname(textdomain)))
 
             context['messages'] = list(catalog)
-            content = GettextRenderer().render('message.pot_t', context)
+            content = GettextRenderer(outdir=self.outdir).render('message.pot_t', context)
 
             pofn = path.join(self.outdir, textdomain + '.pot')
             if should_write(pofn, content):

sphinx/templates/gettext/message.pot_t

@@ -18,7 +18,7 @@ msgstr ""
 {% for message in messages %}
 {% if display_location -%}
 {% for source, line in message.locations -%}
-#: {{ source }}:{{ line }}
+#: {{ relpath(source) }}:{{ line }}
 {% endfor -%}
 {% endif -%}