cleanup: remove pointless r-prefixes on double-quoted strings This is only double-quoted strings. I'll do single-quoted strings as a second step. These had existed because our source transformer didn't turn r"" into b"", so we had tagged some strings as r-strings to get "native" strings on both Pythons. Now that the transformer is gone, we can dispense with this nonsense. Methodology: I ran hg locate 'set:added() or modified() or clean()' | egrep '.*\.py$' | xargs egrep --color=never -n -- \[\^a-z\]r\"\[\^\"\\\\\]\*\"\[\^\"\] in an emacs grep-mode buffer, and then used a keyboard macro to iterate over the results and remove the r prefix as needed. # skip-blame removing unneeded r prefixes left over from Python 3 migration. Differential Revision: https://phab.mercurial-scm.org/D7305

--- a/mercurial/pure/osutil.py	Thu Nov 07 03:59:22 2019 -0800
+++ b/mercurial/pure/osutil.py	Thu Nov 07 13:18:19 2019 -0500
@@ -257,7 +257,7 @@
                 creation = _OPEN_ALWAYS
                 flags |= _O_APPEND
             else:
-                raise ValueError(r"invalid mode: %s" % pycompat.sysstr(mode))
+                raise ValueError("invalid mode: %s" % pycompat.sysstr(mode))
 
             fh = _kernel32.CreateFileA(
                 name,