bisect: avoid adding irrelevant revisions to bisect state When adding new revisions to the bisect state, it only makes sense to add information about revisions that are under consideration (i.e., those that are topologically between the known good and bad revisions). However, if the user passes in a revset (e.g., '!merge()' to exclude merge commits), hg will resolve the revset first and add all matching revisions to the bisect state (which in this case would likely be the majority of revisions in the repo). To avoid this, revisions should only be added to the bisect state if they are between the good and bad revisions (and therefore relevant to the bisection). -- Here are the results of some performance tests using the `mozilla-central` repo (since it is one of the largest freely-available hg repositories in the wild). These tests compare the performance of a locally-built `hg` before and after application of this series. Note that `--noupdate` is passed to avoid including update time (which should not vary across cases). Setup (run between each test): $ hg bisect --reset $ hg bisect --noupdate --bad 56c3ad4bde5c70714b784ccf15d099e0df0f5bde $ hg bisect --noupdate --good 57426696adaf08298af3027fa77486fee0633b13 Test using a revset that returns a very large number of revisions: $ time hg bisect --noupdate --skip '!merge()' > /dev/null Before: real 0m9.398s user 0m9.233s sys 0m0.120s After: real 0m1.513s user 0m1.425s sys 0m0.052s Test using a revset that is expensive to compute: $ time hg bisect --noupdate --skip 'desc("Bug")' > /dev/null Before: real 0m49.853s user 0m49.580s sys 0m0.243s After: real 0m4.120s user 0m4.036s sys 0m0.048s

--- a/mercurial/commands.py	Tue Aug 23 17:31:19 2022 -0400
+++ b/mercurial/commands.py	Tue Aug 23 17:31:27 2022 -0400
@@ -1035,7 +1035,14 @@
     state = hbisect.load_state(repo)
 
     if rev:
-        nodes = [repo.changelog.node(i) for i in logcmdutil.revrange(repo, rev)]
+        revs = logcmdutil.revrange(repo, rev)
+        goodnodes = state[b'good']
+        badnodes = state[b'bad']
+        if goodnodes and badnodes:
+            candidates = repo.revs(b'(%ln)::(%ln)', goodnodes, badnodes)
+            candidates += repo.revs(b'(%ln)::(%ln)', badnodes, goodnodes)
+            revs = candidates & revs
+        nodes = [repo.changelog.node(i) for i in revs]
     else:
         nodes = [repo.lookup(b'.')]
 

--- a/tests/test-bisect2.t	Tue Aug 23 17:31:19 2022 -0400
+++ b/tests/test-bisect2.t	Tue Aug 23 17:31:27 2022 -0400
@@ -784,7 +784,6 @@
   $ hg log -q -r 'bisect(pruned)'
   0:33b1f9bc8bc5
   1:4ca5088da217
-  2:051e12f87bf1
   8:dab8161ac8fc
   11:82ca6f06eccd
   12:9f259202bbe7