# [PATCH] line-log: fix crash when --first-parent is used 7 messages from 2014-10-31 to 2014-11-04. Participants: Tzvetan Mikov, Junio C Hamano, Michael J Gruber. Thread: https://gitlist.dev/t/37859 ## Tzvetan Mikov, 2014-10-31 19:43 Subject: [PATCH] line-log: fix crash when --first-parent is used Message-ID: <1414784636-43155-1-git-send-email-tmikov@gmail.com> URL: https://gitlist.dev/e/1414784636-43155-1-git-send-email-tmikov%40gmail.com ``` line-log tries to access all parents of a commit, but only the first parent has been loaded if "--first-parent" is specified, resulting in a crash. Limit the number of parents to one if "--first-parent" is specified. Reported-by: Eric N. Vander Weele Signed-off-by: Tzvetan Mikov --- line-log.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/line-log.c b/line-log.c index 1008e72..86e7274 100644 --- a/line-log.c +++ b/line-log.c @@ -1141,6 +1141,9 @@ static int process_ranges_merge_commit(struct rev_info *rev, struct commit *comm int i; int nparents = commit_list_count(commit->parents); + if (nparents > 1 && rev->first_parent_only) + nparents = 1; + diffqueues = xmalloc(nparents * sizeof(*diffqueues)); cand = xmalloc(nparents * sizeof(*cand)); parents = xmalloc(nparents * sizeof(*parents)); -- 1.9.1 ``` ## Junio C Hamano, 2014-11-03 20:58 Subject: Re: [PATCH] line-log: fix crash when --first-parent is used Message-ID: URL: https://gitlist.dev/e/xmqqoasoq9vh.fsf%40gitster.dls.corp.google.com In-Reply-To: <1414784636-43155-1-git-send-email-tmikov@gmail.com> ``` Tzvetan Mikov writes: > line-log tries to access all parents of a commit, but only the first > parent has been loaded if "--first-parent" is specified, resulting > in a crash. > > Limit the number of parents to one if "--first-parent" is specified. > > Reported-by: Eric N. Vander Weele > Signed-off-by: Tzvetan Mikov > --- Thomas, how does this one look? Tzvetan, can we have a test for this one? Thanks. > line-log.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/line-log.c b/line-log.c > index 1008e72..86e7274 100644 > --- a/line-log.c > +++ b/line-log.c > @@ -1141,6 +1141,9 @@ static int process_ranges_merge_commit(struct rev_info *rev, struct commit *comm > int i; > int nparents = commit_list_count(commit->parents); > > + if (nparents > 1 && rev->first_parent_only) > + nparents = 1; > + > diffqueues = xmalloc(nparents * sizeof(*diffqueues)); > cand = xmalloc(nparents * sizeof(*cand)); > parents = xmalloc(nparents * sizeof(*parents)); ``` ## Tzvetan Mikov, 2014-11-03 22:09 Subject: Re: [PATCH] line-log: fix crash when --first-parent is used Message-ID: URL: https://gitlist.dev/e/CACt9tMj2GBWC6yRpfKXUk1hnh2ZyBqoV5HDmL0cjfxCiawHT%3Dg%40mail.gmail.com In-Reply-To: ``` On Mon, Nov 3, 2014 at 12:58 PM, Junio C Hamano wrote: >> line-log tries to access all parents of a commit, but only the first >> parent has been loaded if "--first-parent" is specified, resulting >> in a crash. >> >> Limit the number of parents to one if "--first-parent" is specified. >> > [...] > Tzvetan, can we have a test for this one? Here is a sequence of commands to reproduce the crash: git init echo "1" > a.txt && git add a.txt && git commit -m "a" git checkout -b branch echo "2" > b.txt && git add b.txt && git commit -m "b" git checkout master git merge branch --no-ff -m "merge" git log --first-parent -L 1,1:a.txt I am not sure whether you have a requirement for a formal test included with the patch, but if there is one, I am happy to rework it. This is a very simple fix for the crash, though possibly a "real" comprehensive fix may be needed. I am not sure. The real cause is that with "--first-parent" some commit objects are never loaded from disk but may still be accessed. (sorry about my formatting - have to use GMail) regards, Tzvetan ``` ## Michael J Gruber, 2014-11-04 09:34 Subject: Re: [PATCH] line-log: fix crash when --first-parent is used Message-ID: <54589DBB.7040900@drmicha.warpmail.net> URL: https://gitlist.dev/e/54589DBB.7040900%40drmicha.warpmail.net In-Reply-To: ``` Tzvetan Mikov schrieb am 03.11.2014 um 23:09: > On Mon, Nov 3, 2014 at 12:58 PM, Junio C Hamano wrote: > >>> line-log tries to access all parents of a commit, but only the first >>> parent has been loaded if "--first-parent" is specified, resulting >>> in a crash. >>> >>> Limit the number of parents to one if "--first-parent" is specified. >>> > >> [...] >> Tzvetan, can we have a test for this one? > > Here is a sequence of commands to reproduce the crash: > > git init > echo "1" > a.txt && git add a.txt && git commit -m "a" > git checkout -b branch > echo "2" > b.txt && git add b.txt && git commit -m "b" > git checkout master > git merge branch --no-ff -m "merge" > git log --first-parent -L 1,1:a.txt > > I am not sure whether you have a requirement for a formal test > included with the patch, but if there is one, I am happy to > rework it. > > This is a very simple fix for the crash, though possibly > a "real" comprehensive fix may be needed. I am not sure. > The real cause is that with "--first-parent" some commit > objects are never loaded from disk but may still be accessed. > > (sorry about my formatting - have to use GMail) > > regards, > Tzvetan > A test would be nice, yes. Look in t/t4211-line-log.sh - you should be OK if you add a test at the end which does the following: "git checkout parallel-change" so that you have commits with more than 1 parent in the history test "git log -L1,1 b.c" (it core dumps with current git) That is, you don't have to set up merges and history, you can use the existing one. Cheers, Michael ``` ## Tzvetan Mikov, 2014-11-04 20:33 Subject: [PATCH v2] line-log: fix crash when --first-parent is used Message-ID: <1415133217-7824-1-git-send-email-tmikov@gmail.com> URL: https://gitlist.dev/e/1415133217-7824-1-git-send-email-tmikov%40gmail.com In-Reply-To: <1414784636-43155-1-git-send-email-tmikov@gmail.com> ``` line-log tries to access all parents of a commit, but only the first parent has been loaded if "--first-parent" is specified, resulting in a crash. Limit the number of parents to one if "--first-parent" is specified. Reported-by: Eric N. Vander Weele Signed-off-by: Tzvetan Mikov --- PATCH v2: Add a test case (thanks Michael J Gruber) line-log.c | 3 +++ t/t4211-line-log.sh | 5 +++++ 2 files changed, 8 insertions(+) diff --git a/line-log.c b/line-log.c index 1008e72..86e7274 100644 --- a/line-log.c +++ b/line-log.c @@ -1141,6 +1141,9 @@ static int process_ranges_merge_commit(struct rev_info *rev, struct commit *comm int i; int nparents = commit_list_count(commit->parents); + if (nparents > 1 && rev->first_parent_only) + nparents = 1; + diffqueues = xmalloc(nparents * sizeof(*diffqueues)); cand = xmalloc(nparents * sizeof(*cand)); parents = xmalloc(nparents * sizeof(*parents)); diff --git a/t/t4211-line-log.sh b/t/t4211-line-log.sh index 7369d3c..0901b30 100755 --- a/t/t4211-line-log.sh +++ b/t/t4211-line-log.sh @@ -94,4 +94,9 @@ test_expect_success '-L ,Y (Y == nlines + 2)' ' test_must_fail git log -L ,$n:b.c ' +test_expect_success '-L with --first-parent and a merge' ' + git checkout parallel-change && + git log --first-parent -L 1,1:b.c +' + test_done -- 1.9.1 ``` ## Junio C Hamano, 2014-11-04 21:24 Subject: Re: [PATCH v2] line-log: fix crash when --first-parent is used Message-ID: URL: https://gitlist.dev/e/xmqq8ujqpsk6.fsf%40gitster.dls.corp.google.com In-Reply-To: <1415133217-7824-1-git-send-email-tmikov@gmail.com> ``` Tzvetan Mikov writes: > line-log tries to access all parents of a commit, but only the first > parent has been loaded if "--first-parent" is specified, resulting > in a crash. > > Limit the number of parents to one if "--first-parent" is specified. > > Reported-by: Eric N. Vander Weele > Signed-off-by: Tzvetan Mikov > --- > PATCH v2: Add a test case (thanks Michael J Gruber) Thanks, both. The patch looks good (modulo the indentation of nparents assignment, which I'll locally fix up). Will queue. > line-log.c | 3 +++ > t/t4211-line-log.sh | 5 +++++ > 2 files changed, 8 insertions(+) > > diff --git a/line-log.c b/line-log.c > index 1008e72..86e7274 100644 > --- a/line-log.c > +++ b/line-log.c > @@ -1141,6 +1141,9 @@ static int process_ranges_merge_commit(struct rev_info *rev, struct commit *comm > int i; > int nparents = commit_list_count(commit->parents); > > + if (nparents > 1 && rev->first_parent_only) > + nparents = 1; > + > diffqueues = xmalloc(nparents * sizeof(*diffqueues)); > cand = xmalloc(nparents * sizeof(*cand)); > parents = xmalloc(nparents * sizeof(*parents)); > diff --git a/t/t4211-line-log.sh b/t/t4211-line-log.sh > index 7369d3c..0901b30 100755 > --- a/t/t4211-line-log.sh > +++ b/t/t4211-line-log.sh > @@ -94,4 +94,9 @@ test_expect_success '-L ,Y (Y == nlines + 2)' ' > test_must_fail git log -L ,$n:b.c > ' > > +test_expect_success '-L with --first-parent and a merge' ' > + git checkout parallel-change && > + git log --first-parent -L 1,1:b.c > +' > + > test_done ``` ## Tzvetan Mikov, 2014-11-04 21:41 Subject: Re: [PATCH v2] line-log: fix crash when --first-parent is used Message-ID: URL: https://gitlist.dev/e/CACt9tMi24QyvdpCk-tmU5U8jbP8eYhaNm4zWu6PqcKsJQ%3DOsYw%40mail.gmail.com In-Reply-To: ``` On Tue, Nov 4, 2014 at 1:24 PM, Junio C Hamano wrote: > Thanks, both. The patch looks good (modulo the indentation of > nparents assignment, which I'll locally fix up). > > Will queue. Awesome, thanks! (I can't believe I missed that tab. Well, at least one of my two lines was correct :-) ) regards, Tzvetan ```