Re: [PATCH] refspec: allow @ on the left-hand side of refspecs
From: Brandon Williams <hidden>
Date: 2018-07-30 17:50:56
On 07/29, brian m. carlson wrote:
The object ID parsing machinery is aware of "@" as a synonym for "HEAD" and this is documented accordingly in gitrevisions(7). The push documentation describes the source portion of a refspec as "any arbitrary 'SHA-1 expression'"; however, "@" is not allowed on the left-hand side of a refspec, since we attempt to check for it being a valid ref name and fail (since it is not). Teach the refspec machinery about this alias and silently substitute "HEAD" when we see "@". This handles the fact that HEAD is a symref and preserves its special behavior. We need not handle other arbitrary object ID expressions (such as "@^") when pushing because the revision machinery already handles that for us.
So this claims that using "@^" should work despite not accounting for it explicitly or am I misreading? Unless I'm mistaken, it looks like we don't really support arbitrary rev syntax in refspecs since "HEAD^" doesn't work either.
Signed-off-by: brian m. carlson <redacted> --- I probably type "git push upstream HEAD" from five to thirty times a day, many of those where I typo "HEAD", so I decided to implement the shorter form. This design handles @ as HEAD in both fetch and push, whereas alternate solutions would not.
I'm always a fan of finding shortcuts and reducing how much I type, so thank you :)
quoted hunk ↗ jump to hunk
check_refname_format explicitly rejects "@"; I tried at first to simply ignore that with a flag, but we end up calling that from several other places in the codebase and rejecting it and all of those places would have needed updating. I thought about putting the if/else logic in a function, but since it's just four lines, I decided not to. However, if people think it would be tidier, I can do so. Note that the test portion of the patch is best read with git diff -w; the current version is very noisy. refspec.c | 6 ++- t/t5516-fetch-push.sh | 104 +++++++++++++++++++++--------------------- 2 files changed, 58 insertions(+), 52 deletions(-)diff --git a/refspec.c b/refspec.c index e8010dce0c..57c2f65104 100644 --- a/refspec.c +++ b/refspec.c@@ -62,8 +62,12 @@ static int parse_refspec(struct refspec_item *item, const char *refspec, int fet return 0; } + if (llen == 1 && lhs[0] == '@') + item->src = xstrdup("HEAD"); + else + item->src = xstrndup(lhs, llen); +
This is probably the easiest place to put the aliasing logic so I don't have any issue with including it here. -- Brandon Williams