lfs: don't skip locally available blobs when verifying

The `skipflags` config was introduced in a2ab9ebcd85b, which specifically calls
out downloading and storing all blobs as potentially too expensive.  But I don't
see any reason to skip blobs that are already available locally.  Hashing the
blob is the only way to indirectly verify the rawdata content stored in the
revlog.

(The note in that commit about skipping renamed is still correct, but the reason
given about needing fulltext isn't.)

Differential Revision: https://phab.mercurial-scm.org/D7712

hgext/lfs/__init__.py

@@ -405,7 +405,8 b' def debuglfsupload(ui, repo, **opts):'
 
 
 @eh.wrapcommand(
-    b'verify', opts=[(b'', b'no-lfs', None, _(b'skip all lfs blob content'))]
+    b'verify',
+    opts=[(b'', b'no-lfs', None, _(b'skip missing lfs blob content'))],
 )
 def verify(orig, ui, repo, **opts):
     skipflags = repo.ui.configint(b'verify', b'skipflags')

hgext/lfs/wrapper.py

@@ -225,6 +225,21 b' def filelogsize(orig, self, rev):'
     return orig(self, rev)
 
 
[e-mail](revlog, b'_verify_revision')
+def _verify_revision(orig, rl, skipflags, state, node):
+    if _islfs(rl, node=node):
+        rawtext = rl.rawdata(node)
+        metadata = pointer.deserialize(rawtext)
+
+        # Don't skip blobs that are stored locally, as local verification is
+        # relatively cheap and there's no other way to verify the raw data in
+        # the revlog.
+        if rl.opener.lfslocalblobstore.has(metadata.oid()):
+            skipflags &= ~revlog.REVIDX_EXTSTORED
+
+    orig(rl, skipflags, state, node)
+
+
 @eh.wrapfunction(context.basefilectx, b'cmp')
 def filectxcmp(orig, self, fctx):
     """returns True if text is different than fctx"""

tests/test-lfs.t

@@ -804,6 +804,7 b' Verify will not try to download lfs blob'
   checking manifests
   crosschecking files in changesets and manifests
   checking files
+  lfs: found 22f66a3fc0b9bf3f012c814303995ec07099b3a9ce02a7af84b5970811074a3b in the local lfs store
   checked 5 changesets with 10 changes to 4 files
 
 Verify will not try to download lfs blobs, if told not to by the config option
@@ -815,6 +816,7 b' Verify will not try to download lfs blob'
   checking manifests
   crosschecking files in changesets and manifests
   checking files
+  lfs: found 22f66a3fc0b9bf3f012c814303995ec07099b3a9ce02a7af84b5970811074a3b in the local lfs store
   checked 5 changesets with 10 changes to 4 files
 
 Verify will copy/link all lfs objects into the local store that aren't already