From: Jeff King Date: Tue, 8 Jul 2008 04:38:54 +0000 (-0400) Subject: avoid null SHA1 in oldest reflog X-Git-Tag: v1.6.0-rc0~112 X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=d1a4489a56e2ceac8e7dc9eb277a9f36fec725c5;p=git.git avoid null SHA1 in oldest reflog When the user specifies a ref by a reflog entry older than one we have (e.g., "HEAD@{20 years ago"}), we issue a warning and give them the "from" value of the oldest reflog entry. That is, we say "we don't know what happened before this entry, but before this we know we had some particular SHA1". However, the oldest reflog entry is often a creation event such as clone or branch creation. In this case, the entry claims that the ref went from "00000..." (the null sha1) to the new value, and the reflog lookup returns the null sha1. While this is technically correct (the entry tells us that the ref didn't exist at the specified time) it is not terribly useful to the end user. What they probably want instead is "the oldest useful sha1 that this ref ever had". This patch changes the behavior such that if the oldest ref would return the null sha1, it instead returns the first value the ref ever had. We never discovered this problem in the test scripts because we created "fake" reflogs that had only a specified segment of history. This patch updates the tests with a creation event at the beginning of history. Signed-off-by: Jeff King Acked-by: Shawn O. Pearce Signed-off-by: Junio C Hamano --- diff --git a/refs.c b/refs.c index 9e8e8581b..6c6e9e5e1 100644 --- a/refs.c +++ b/refs.c @@ -1412,6 +1412,10 @@ int read_ref_at(const char *ref, unsigned long at_time, int cnt, unsigned char * tz = strtoul(tz_c, NULL, 10); if (get_sha1_hex(logdata, sha1)) die("Log %s is corrupt.", logfile); + if (is_null_sha1(sha1)) { + if (get_sha1_hex(logdata + 41, sha1)) + die("Log %s is corrupt.", logfile); + } if (msg) *msg = ref_msg(logdata, logend); munmap(log_mapped, mapsz); diff --git a/t/t1400-update-ref.sh b/t/t1400-update-ref.sh index f387d46f1..ca99d3761 100755 --- a/t/t1400-update-ref.sh +++ b/t/t1400-update-ref.sh @@ -155,7 +155,8 @@ rm -f .git/$m .git/logs/$m expect git update-ref $m $D cat >.git/logs/$m < 1117150320 -0500 +0000000000000000000000000000000000000000 $C $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150320 -0500 +$C $A $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150350 -0500 $A $B $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150380 -0500 $F $Z $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150680 -0500 $Z $E $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150980 -0500 @@ -186,6 +187,12 @@ test_expect_success \ 'Query "master@{May 26 2005 23:32:00}" (exactly history start)' \ 'rm -f o e git rev-parse --verify "master@{May 26 2005 23:32:00}" >o 2>e && + test '"$C"' = $(cat o) && + test "" = "$(cat e)"' +test_expect_success \ + 'Query "master@{May 26 2005 23:32:30}" (first non-creation change)' \ + 'rm -f o e + git rev-parse --verify "master@{May 26 2005 23:32:30}" >o 2>e && test '"$A"' = $(cat o) && test "" = "$(cat e)"' test_expect_success \