revert: restore the ability to revert across case only renames (issue4481)

This regressed in 5e16fe6fdd32, in what looks like an unrelated change.

It seems sufficient to pass 'ignoremissing=True', but the restored try/except
has been there for six years since 41bb88cb913e, so this seems safer for now.
Note that renaming directories in the filename doesn't appear to work- not sure
if this would end up throwing a different type of error when that is fixed.

mercurial/cmdutil.py

@@ -3084,7 +3084,10 b' def _performrevert(repo, parents, ctx, a'
         repo.dirstate.drop(f)
     for f in actions['remove'][0]:
         audit_path(f)
+        try:
         util.unlinkpath(repo.wjoin(f))
+        except OSError:
+            pass
         repo.dirstate.remove(f)
     for f in actions['drop'][0]:
         audit_path(f)

tests/test-casefolding.t

@@ -153,6 +153,23 b' issue 3342: file in nested directory cau'
   $ mkdir -p a/B/c/D
   $ echo e > a/B/c/D/e
   $ hg add a/B/c/D/e
+  $ hg ci -m 'add e'
+
+issue 4481: revert across case only renames
+  $ hg mv a/B/c/D/e a/B/c/d/E
+  $ hg ci -m "uppercase E"
+  $ echo 'foo' > a/B/c/D/E
+  $ hg ci -m 'e content change'
+  $ hg revert --all -r 0
+  removing a\B\c\D\E
+  adding a\B\c\D\e
+  $ find * | sort
+  a
+  a/B
+  a/B/c
+  a/B/c/D
+  a/B/c/D/e
+  a/B/c/D/e.orig
 
   $ cd ..