hgweb: show as same parents as "hg parents -r REV FILE" in pages for file
Before this patch, "parents" in pages for file doesn't show as same
parents as "hg parents -r REV FILE", when the specified file is not
modified in the specified revision.
For example, it is assumed that revision A, B and D change file "f".
changelog (A) ---> (B) ---> (C) ---> (D)
filelog "f" (x) ---> (y) ------------> (z)
"/file/D/f" invokes "webutil.parents()" with filectx(z) gotten from
changectx(D), and it returns changectx(B). This is as same result as
"hg parents -r D f".
In the other hand, "/file/C/f" invokes "webutil.parents()" with
filectx(y') gotten from changectx(C), and it returns changectx(A),
because filectx(y') is linked to changectx(B), and works like
filectx(y) in some cases.
In this case, revision B is hidden from users browsing file "f" in
revision C.
This patch shows as same parents as "hg parents -r REV FILE" in pages
for file, by making "webutil.parents()" return:
- "linkrev()"-ed revision only, if:
- specified context instance is "filectx" (because
"webutil.parents()" is invoked with changectx, too), and
- (1) the revision from which filectx is gotten and (2) the one to
which filectx is linked are different from each other
- revision gotten from "ctx.parents()", otherwise
Testing that hghave does not crash when checking features
$ "$TESTDIR/hghave" --test-features 2>/dev/null