t6600: add clock-skew topologies and step counts for edge cases

index 574777d809..f712301a2d 100755 --- a/t/t6600-test-reach.sh +++ b/t/t6600-test-reach.sh @@ -140,6 +140,48 @@ test_expect_success 'setup' ' git branch -f pi-X-br "$pi_x" && git tag pi-X "$pi_x" && + # Clock-skew topology for side-exhaustion testing. + # D is the correct merge base but has a higher committer date + # than C (its child). With date ordering, D would be dequeued + # before C, causing side-exhaustion to fire too early. + # Generation ordering prevents this by visiting children + # before parents regardless of dates. + # + # se-A (date 7000) --> se-C (date 3000) --> se-D (date 5000) --> se-root (date 4000) + # se-B (date 6000) --> se-D + # + se_root=$(skew_commit 4000 se-root) && + se_D=$(skew_commit 5000 se-D -p "$se_root") && + se_C=$(skew_commit 3000 se-C -p "$se_D") && + se_A=$(skew_commit 7000 se-A -p "$se_C") && + se_B=$(skew_commit 6000 se-B -p "$se_D") && + git branch -f se-A "$se_A" && + git branch -f se-B "$se_B" && + git tag se-D "$se_D" && + + # Clock-skew topology with redundant ancestor for + # side-exhaustion testing. MB1 is the correct merge base; + # MB2 is its parent. A reaches MB2 via E (high date) and + # MB1 via C (low date). B reaches MB1 via D. With date + # ordering, side-exhaustion would fire before C is dequeued, + # missing MB1. Generation ordering ensures both are found. + # + # se2-A (date 8000) --> se2-C (date 2000) --> se2-MB1 (date 5000) --> se2-MB2 (date 4000) --> se2-root (date 1000) + # se2-A --> se2-E (date 6500) --> se2-MB2 + # se2-B (date 7000) --> se2-D (date 6000) --> se2-MB1 + # + se2_root=$(skew_commit 1000 se2-root) && + se2_MB2=$(skew_commit 4000 se2-MB2 -p "$se2_root") && + se2_MB1=$(skew_commit 5000 se2-MB1 -p "$se2_MB2") && + se2_C=$(skew_commit 2000 se2-C -p "$se2_MB1") && + se2_D=$(skew_commit 6000 se2-D -p "$se2_MB1") && + se2_E=$(skew_commit 6500 se2-E -p "$se2_MB2") && + se2_A=$(skew_commit 8000 se2-A -p "$se2_C" -p "$se2_E") && + se2_B=$(skew_commit 7000 se2-B -p "$se2_D") && + git branch -f se2-A "$se2_A" && + git branch -f se2-B "$se2_B" && + git tag se2-MB1 "$se2_MB1" && + git commit-graph write --reachable && mv .git/objects/info/commit-graph commit-graph-full && chmod u+w commit-graph-full && @@ -323,7 +365,8 @@ test_expect_success 'get_merge_bases_many:pending-stale' ' echo "get_merge_bases_many(A,X):" && git rev-parse ps-B } >expect && - test_all_modes get_merge_bases_many + test_all_modes get_merge_bases_many && + test_paint_down_steps 6 6 6 6 ' test_expect_success 'get_merge_bases_many:infinity-both-sides' ' @@ -337,7 +380,34 @@ test_expect_success 'get_merge_bases_many:infinity-both-sides' ' echo "get_merge_bases_many(A,X):" && git rev-parse pi-B } >expect && - test_all_modes get_merge_bases_many + test_all_modes get_merge_bases_many && + test_paint_down_steps 5 5 5 5 +' + +test_expect_success 'setup mixed finite/INFINITY topology' ' + # Create a commit outside all saved commit-graph files so it always + # has INFINITY generation, while its parent (ps-X) is in the graph + # with a finite generation. Use the ps-* orphan topology so we do + # not pollute the grid-based rev-list tests. + git checkout ps-X && + test_env GIT_TEST_COMMIT_GRAPH= test_commit pm-INF +' + +test_expect_success 'get_merge_bases_many:mixed-finite-infinity' ' + # One tip (pm-INF) is outside the commit-graph with INFINITY + # generation; the other (ps-B) is in the graph with finite + # generation. The walk starts in the INFINITY region and crosses + # into the finite region where side-exhaustion can fire. + cat >input <<-\EOF && + A:pm-INF + X:ps-B + EOF + { + echo "get_merge_bases_many(A,X):" && + git rev-parse ps-X + } >expect && + test_all_modes get_merge_bases_many && + test_paint_down_steps 3 3 3 3 ' test_expect_success 'merge-base --all commit-walk steps' ' @@ -347,6 +417,30 @@ test_expect_success 'merge-base --all commit-walk steps' ' test_paint_down_steps 81 80 81 81 ' +test_expect_success 'merge-base --all with clock skew (side-exhaustion)' ' + # Verify correct merge base under clock skew. se-D (the + # merge base) has a higher date than its child se-C. + # Generation ordering ensures se-C is visited before se-D, + # so P1 paint propagates correctly and se-D is found. + >input && + git rev-parse se-D >expect && + run_all_modes git merge-base --all se-A se-B && + test_paint_down_steps 6 4 6 6 +' + +test_expect_success 'merge-base --all with clock skew and redundant ancestor (side-exhaustion)' ' + # Verify correct merge base when clock skew could cause a + # too-deep result. MB1 is the correct merge base; MB2 is + # its ancestor. A reaches MB2 via E (high date) and MB1 + # via C (low date). Generation ordering ensures C is + # visited before side-exhaustion fires, so MB1 is found + # and remove_redundant correctly discards MB2. + >input && + git rev-parse se2-MB1 >expect && + run_all_modes git merge-base --all se2-A se2-B && + test_paint_down_steps 8 7 8 8 +' + test_expect_success 'reduce_heads' ' cat >input <<-\EOF && X:commit-1-10