On 29/05/2018 01:06, SZEDER Gábor wrote:
So, without investing nearly enough time to understand what is going
on, I massaged the above diffs into this:
Cool.
+ treesame_parents = xmalloc(sizeof(*treesame_parents));
There's no need to actually record a list here. This is just for the
simple history. We are only interested into becoming a non-merge to 1
treesame parent, so I think we just need to record a pointer to the
first one we see, just as this would exit immediately for the first
relevant one. For the full-history case, we already have the full "which
parents are treesame" recording mechanism just above, but it only kicks
in for merge commits and only when settings require it. Adding a malloc
here would be significant machinery overhead.
FWIW, the test suite passes with the above patch applied.
I doubt there's an existing case like this anywhere in the revision test
suite :) . And this patch is focused enough that it *should* only be
changing the behaviour of this very specific case. As such, it does feel
a little like a kludge, but I think it's fine because it's aligning the
simple-history analysis with the "analyse relevant parents if any, else
analyse irrelevant" rule of the full-history.
And here is the small PoC test case to illustrate the issue, which
fails without but succeeds with the above patch. Eventually it should
be part of 't6012-rev-list-simplify.sh', of course, but I haven't
looked into that yet.
It may be there's enough criss-crossy history to test here to merit
breaking out into a second test series.
+# B---M2 master
+# / \ /
+# A X
+# \ / \
+# C---M1 b2
+#
+# and modify 'file' in commits 'A' and 'B', so one of 'M1's parents
+# ('B') is TREESAME wrt. 'file'.
I guess we'll be wanting test cases for A..B2, B..B2 and C..B2, and some
where the the base is "some other child of B or C". "B..B2" is no
longer a pure set subtraction for simplification as B is UNINTERESTING
(ie not in the set) but RELEVANT (because you named it as a bottom
commit), so B..B2 actually still leaves M1 with 2 relevant parents.
You'd want test cases covering B relevant+C irrelevant and B
irrelevant+C relevant, which means subtracting them without naming them
- so name a child of one.
And then we need to think about whether we want it displayed in each of
the other modes for each of those queries...
Kevin
