[bugfix] Suppress error in CosmeticChangesToolkit.cleanUpLinks()

- no longer retry api request on ServerError which includes
  FatalServerError. ServerError is raised when a requests.ReadTimeout
  or  requests.ConnectTimeout occurs.
- suppress ServerError in CosmeticChangesToolkit.cleanUpLinks()
  when calling site.isInterwikiLink() because the corresponding
  site may be down.

Bug: T337045
Change-Id: I499bc1d7cc2bbd98cac20548a5e40c9dbf314ec2
---
M pywikibot/cosmetic_changes.py
M pywikibot/data/api/_requests.py
2 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/pywikibot/cosmetic_changes.py b/pywikibot/cosmetic_changes.py
index 1e13373..845d6ce 100644
--- a/pywikibot/cosmetic_changes.py
+++ b/pywikibot/cosmetic_changes.py
@@ -64,9 +64,8 @@
 from urllib.parse import urlparse, urlunparse
 
 import pywikibot
-from pywikibot import textlib
+from pywikibot import exceptions, textlib
 from pywikibot.backports import Callable, Match, Pattern
-from pywikibot.exceptions import InvalidTitleError
 from pywikibot.textlib import (
     FILE_LINK_REGEX,
     MultiTemplateMatchBuilder,
@@ -532,8 +531,10 @@
             oldlink = url2string(match.group(),
                                  encodings=self.site.encodings())
 
-            is_interwiki = self.site.isInterwikiLink(titleWithSection)
-            if is_interwiki:
+            is_interwiki = None
+            with suppress(exceptions.ServerError):
+                is_interwiki = self.site.isInterwikiLink(titleWithSection)
+            if is_interwiki is not False:
                 return oldlink
 
             # The link looks like this:
@@ -541,10 +542,9 @@
             # We only work on namespace 0 because pipes and linktrails work
             # differently for images and categories.
             page = pywikibot.Page(pywikibot.Link(titleWithSection, self.site))
-            try:
+            in_main_namespace = None
+            with suppress(exceptions.InvalidTitleError):
                 in_main_namespace = page.namespace() == 0
-            except InvalidTitleError:
-                in_main_namespace = False
             if not in_main_namespace:
                 return oldlink
 
diff --git a/pywikibot/data/api/_requests.py b/pywikibot/data/api/_requests.py
index 3b63cb2..61dad40 100644
--- a/pywikibot/data/api/_requests.py
+++ b/pywikibot/data/api/_requests.py
@@ -30,10 +30,10 @@
 from pywikibot.exceptions import (
     Client414Error,
     Error,
-    FatalServerError,
     MaxlagTimeoutError,
     NoUsernameError,
     Server504Error,
+    ServerError,
     SiteDefinitionError,
 )
 from pywikibot.login import LoginStatus
@@ -694,7 +694,7 @@
                 pywikibot.warning(
                     'Caught HTTP 414 error, although not using GET.')
                 raise
-        except (ConnectionError, FatalServerError):
+        except (ConnectionError, ServerError):
             # This error is not going to be fixed by just waiting
             pywikibot.error(traceback.format_exc())
             raise

