Drop the doctype check

news/10903.removal.rst

@@ -0,0 +1 @@
+Drop the doctype check for the simple index protocol.

src/pip/_internal/exceptions.py

@@ -181,30 +181,6 @@ class UninstallationError(PipError):
     """General exception during uninstallation"""
 
 
-class BadHTMLDoctypeDeclaration(DiagnosticPipError):
-    reference = "bad-index-doctype"
-
-    def __init__(self, *, url: str) -> None:
-        super().__init__(
-            kind="warning",
-            message=(
-                "The package index page being used does not have a proper HTML "
-                "doctype declaration."
-            ),
-            context=f"Problematic URL: {escape(url)}",
-            note_stmt="This is an issue with the page at the URL mentioned above.",
-            hint_stmt=(
-                "You might need to reach out to the owner of that package index, "
-                "to get this fixed. "
-                "See https://github.com/pypa/pip/issues/10825 for context."
-            ),
-        )
-
-
-class MissingHTMLDoctypeDeclaration(BadHTMLDoctypeDeclaration):
-    reference = "missing-index-doctype"
-
-
 class MissingPyProjectBuildRequires(DiagnosticPipError):
     """Raised when pyproject.toml has `build-system`, but no `build-system.requires`."""
 

src/pip/_internal/index/collector.py

@@ -32,11 +32,7 @@
 from pip._vendor.requests import Response
 from pip._vendor.requests.exceptions import RetryError, SSLError
 
-from pip._internal.exceptions import (
-    BadHTMLDoctypeDeclaration,
-    MissingHTMLDoctypeDeclaration,
-    NetworkConnectionError,
-)
+from pip._internal.exceptions import NetworkConnectionError
 from pip._internal.models.link import Link
 from pip._internal.models.search_scope import SearchScope
 from pip._internal.network.session import PipSession
@@ -401,33 +397,12 @@ class HTMLLinkParser(HTMLParser):
 
     def __init__(self, url: str) -> None:
         super().__init__(convert_charrefs=True)
-        self._dealt_with_doctype_issues = False
 
         self.url: str = url
         self.base_url: Optional[str] = None
         self.anchors: List[Dict[str, Optional[str]]] = []
 
-    def handle_decl(self, decl: str) -> None:
-        self._dealt_with_doctype_issues = True
-        match = re.match(
-            r"""doctype\s+html\s*(?:SYSTEM\s+(["'])about:legacy-compat\1)?\s*$""",
-            decl,
-            re.IGNORECASE,
-        )
-        if match is None:
-            logger.warning(
-                "[present-diagnostic] %s",
-                BadHTMLDoctypeDeclaration(url=self.url),
-            )
-
     def handle_starttag(self, tag: str, attrs: List[Tuple[str, Optional[str]]]) -> None:
-        if not self._dealt_with_doctype_issues:
-            logger.warning(
-                "[present-diagnostic] %s",
-                MissingHTMLDoctypeDeclaration(url=self.url),
-            )
-            self._dealt_with_doctype_issues = True
-
         if tag == "base" and self.base_url is None:
             href = self.get_href(attrs)
             if href is not None:

tests/unit/test_collector.py

@@ -551,7 +551,7 @@ def test_parse_link_handles_deprecated_usage_properly() -> None:
     assert "pkg1-2.0" in parsed_links[1].url
 
 
-def test_parse_links_presents_warning_on_missing_doctype(
+def test_parse_links_no_warning_on_missing_doctype(
     caplog: pytest.LogCaptureFixture,
 ) -> None:
     html = b'<a href="/pkg1-1.0.tar.gz"></a><a href="/pkg1-2.0.tar.gz"></a>'
@@ -565,10 +565,10 @@ def test_parse_links_presents_warning_on_missing_doctype(
     assert "pkg1-1.0" in parsed_links[0].url
     assert "pkg1-2.0" in parsed_links[1].url
 
-    assert len(caplog.records) == 1
+    assert len(caplog.records) == 0
 
 
-def test_parse_links_presents_warning_on_html4_doctype(
+def test_parse_links_no_warning_on_html4_doctype(
     caplog: pytest.LogCaptureFixture,
 ) -> None:
     html = (
@@ -586,7 +586,7 @@ def test_parse_links_presents_warning_on_html4_doctype(
     assert "pkg1-1.0" in parsed_links[0].url
     assert "pkg1-2.0" in parsed_links[1].url
 
-    assert len(caplog.records) == 1
+    assert len(caplog.records) == 0
 
 
 @mock.patch("pip._internal.index.collector.raise_for_status")