pyupgrade: rewrite `yield` statements in a loop to `yield from` This is the `legacy` fixer in `pyupgrade`, with the `yield` statement yielding loop commented back in. This seems to help pytype in some cases, and hurt it in others. But that can be manually fixed later. Note that it's possibly buggy in that it aggressively changed `import-checker.py` to `yield from 'fcntl', 'grp', 'pwd', 'select', 'termios': # Unix only`, which is invalid syntax. Possibly it needed help from the token fixer that I've disabled locally (because that wants to make a bunch of unrelated changes). Just change those few places to yield from a list, to avoid having to constantly revert that.

--- a/mercurial/smartset.py	Sun Jan 05 22:23:31 2025 -0500
+++ b/mercurial/smartset.py	Sun Jan 05 22:26:16 2025 -0500
@@ -544,8 +544,7 @@
         elif val2 is not None:
             # might have been equality and both are empty
             yield val2
-        for val in it:
-            yield val
+        yield from it
 
 
 class addset(abstractsmartset):