Max Kirillov <max@xxxxxxxxxx> writes: > Reverse blame can be used to locate removal of lines which does not > change adjacent lines. Such edits do not appear in non-reverse blame, > because the adjacent lines last changed commit is older history, before > the edit. > > For a big and active project which uses topic branches, or analogous > feature, for example pull-requests, the history can contain many > concurrent branches, and even after an edit merged into the target > branch, there are still many (sometimes several tens or even hundreds) > topic branch which do not contain it: > > a0--a1-----*a2-*a3-a4...-*a100 > |\ / / / > | b0-B1..bN / / > |\ / / > | c0.. ..cN / > \ / > z0.. ..zN > > Here, the '*'s mark the first parent in merge, and uppercase B1 - the > commit where the line being blamed for was removed. Since commits cN-zN > do not contain the B1, the still have the line removed in B1, and > reverce blame can report that the last commit for the line was zN > (meaning that it was removed in a100). In fact it really does return > some very late commit, and this makes it unusable for finding the B1 > commit. > > The search could be done by blame --reverse --first-parent. For range > a0..a100 it would return a1, and then only one additional blame along > the a0..bN will return the desired commit b0. But combining --reverse > and --first-parent was forbidden in 95a4fb0eac, because incorrectly > specified range could produce unexpected and meaningless result. > > Add test which describes the expected behavior of > `blame --reverse --first-parent` in the case described above. > > Signed-off-by: Max Kirillov <max@xxxxxxxxxx> > --- There were a few obvious typos I spotted but other than that a very understandable description. Will queue. Thanks. > t/t8009-blame-vs-topicbranches.sh | 36 ++++++++++++++++++++++++++++++++++++ > 1 file changed, 36 insertions(+) > create mode 100755 t/t8009-blame-vs-topicbranches.sh > > diff --git a/t/t8009-blame-vs-topicbranches.sh b/t/t8009-blame-vs-topicbranches.sh > new file mode 100755 > index 0000000..175ad37 > --- /dev/null > +++ b/t/t8009-blame-vs-topicbranches.sh > @@ -0,0 +1,36 @@ > +#!/bin/sh > + > +test_description='blaming trough history with topic branches' > +. ./test-lib.sh > + > +# Creates the history shown below. '*'s mark the first parent in the merges. > +# The only line of file.t is changed in commit B2 > +# > +# +---C1 > +# / \ > +# A0--A1--*A2--*A3 > +# \ / > +# B1-B2 > +# > +test_expect_success setup ' > + test_commit A0 file.t line0 && > + test_commit A1 && > + git reset --hard A0 && > + test_commit B1 && > + test_commit B2 file.t line0changed && > + git reset --hard A1 && > + test_merge A2 B2 && > + git reset --hard A1 && > + test_commit C1 && > + git reset --hard A2 && > + test_merge A3 C1 > + ' > + > +test_expect_failure 'blame --reverse --first-parent finds A1' ' > + git blame --porcelain --reverse --first-parent A0..A3 -- file.t >actual_full && > + head -n 1 <actual_full | sed -e "s/ .*//" >actual && > + git rev-parse A1 >expect && > + test_cmp expect actual > + ' > + > +test_done -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html