Based on a recent list of rules for flag/option precedence for git-pull[1] from Junio (particularly focusing on rebase vs. merge vs. fast-forward), here's an attempt to implement and document it. Given multiple recent surprises from users about some of these behaviors[2][3] and a coworker just yesterday expressing some puzzlement with git-pull and rebase vs. merge, it seems like a good time to address some of these issues. Since the handling of conflicting options was holding up two of Alex's patches[4][5], and his patches fix some of the tests, I also include those two patches in my series, with a few small changes to the first (so I've kept him as author) and more substantial changes to the second (so I've given him an Initial-patch-by attribution). Changes since v2: * Remove some unnecessary changes in patch 4, pointed out by Junio. Changes since v1: * Rebased on latest master (resolved a simple conflict with dd/test-stdout-count-lines) * Patch 1: based on feedback from Junio, fixed some style issues, clarified function names, added a few new tests, and took a stab at fixing up the comments and test descriptions (but still unsure if I hit the mark on the last point) * Patch 2: changed the test expectations for one of the multiple head tests as per Junio's suggestion, and made one of the other tests expect a more specific error message * Patches 4 & 5 were squashed and fixed: these now address a submodule bug interaction with --ff-only * Old patch 6 (now 5): added a code comment explaining a subtle point * Old patch 8 (now 7): a few more documentation updates, especially making --ff-only not sound merge-specific * Old patch 9 (now 8): Updates for new test expectation from patch 2 Quick overview: * Patches 1-2: new testcases (see the commit messages for the rules) * Patch 3: Alex's recent patch (abort if --ff-only but can't do so) * Patches 4-6: fix the precedence parts Alex didn't cover * Patch 7: Alex's other patch, abort if rebase vs. merge not specified * Patch 8: Compatibility of git-pull with merge-options.txt (think rebasing) * Patch 9: Fix multiple heads handling too [1] https://lore.kernel.org/git/xmqqwnpqot4m.fsf@gitster.g/ [2] https://lore.kernel.org/git/CAL3xRKdOyVWvcLXK7zoXtFPiHBjgL24zi5hhg+3yjowwSUPgmg@xxxxxxxxxxxxxx/ [3] https://lore.kernel.org/git/c62933fb-96b2-99f5-7169-372f486f6e39@xxxxxxxxxx/ [4] https://lore.kernel.org/git/20210711012604.947321-1-alexhenrie24@xxxxxxxxx/ [5] https://lore.kernel.org/git/20210627000855.530985-1-alexhenrie24@xxxxxxxxx/ Alex Henrie (1): pull: abort if --ff-only is given and fast-forwarding is impossible Elijah Newren (7): t7601: test interaction of merge/rebase/fast-forward flags and options t7601: add tests of interactions with multiple merge heads and config pull: since --ff-only overrides, handle it first pull: make --rebase and --no-rebase override pull.ff=only pull: abort by default when fast-forwarding is not possible pull: update docs & code for option compatibility with rebasing pull: fix handling of multiple heads Documentation/git-merge.txt | 2 + Documentation/git-pull.txt | 21 +-- Documentation/merge-options.txt | 40 ++++++ advice.c | 5 + advice.h | 1 + builtin/merge.c | 2 +- builtin/pull.c | 55 +++++-- t/t4013-diff-various.sh | 2 +- t/t5520-pull.sh | 20 +-- t/t5521-pull-options.sh | 4 +- t/t5524-pull-msg.sh | 4 +- t/t5553-set-upstream.sh | 14 +- t/t5604-clone-reference.sh | 4 +- t/t6402-merge-rename.sh | 18 +-- t/t6409-merge-subtree.sh | 6 +- t/t6417-merge-ours-theirs.sh | 10 +- t/t7601-merge-pull-config.sh | 244 +++++++++++++++++++++++++++++--- t/t7603-merge-reduce-heads.sh | 2 +- 18 files changed, 371 insertions(+), 83 deletions(-) base-commit: daab8a564f8bbac55f70f8bf86c070e001a9b006 Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-1049%2Fnewren%2Fhandle-pull-option-precedence-v3 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-1049/newren/handle-pull-option-precedence-v3 Pull-Request: https://github.com/git/git/pull/1049 Range-diff vs v2: 1: 17560927211 = 1: 17560927211 t7601: test interaction of merge/rebase/fast-forward flags and options 2: 66fe7f7f934 = 2: 66fe7f7f934 t7601: add tests of interactions with multiple merge heads and config 3: c45cd239666 = 3: c45cd239666 pull: abort if --ff-only is given and fast-forwarding is impossible 4: 1a821d3b1dd ! 4: 0682b2250f4 pull: since --ff-only overrides, handle it first @@ builtin/pull.c: int cmd_pull(int argc, const char **argv, const char *prefix) if (opt_rebase) { int ret = 0; -@@ builtin/pull.c: int cmd_pull(int argc, const char **argv, const char *prefix) - submodule_touches_in_range(the_repository, &upstream, &curr_head)) - die(_("cannot rebase with locally recorded submodule modifications")); - -- if (can_ff) { -- /* we can fast-forward this without invoking rebase */ -- opt_ff = "--ff-only"; -- ret = run_merge(); -- } else { -- ret = run_rebase(&newbase, &upstream); -- } -+ ret = run_rebase(&newbase, &upstream); - - if (!ret && (recurse_submodules == RECURSE_SUBMODULES_ON || - recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND)) - - ## t/t5520-pull.sh ## -@@ t/t5520-pull.sh: test_expect_success '--rebase (merge) fast forward' ' - # The above only validates the result. Did we actually bypass rebase? - git reflog -1 >reflog.actual && - sed "s/^[0-9a-f][0-9a-f]*/OBJID/" reflog.actual >reflog.fuzzy && -- echo "OBJID HEAD@{0}: pull --rebase . ff: Fast-forward" >reflog.expected && -+ echo "OBJID HEAD@{0}: pull --rebase . ff (finish): returning to refs/heads/to-rebase" >reflog.expected && - test_cmp reflog.expected reflog.fuzzy - ' - -@@ t/t5520-pull.sh: test_expect_success '--rebase (am) fast forward' ' - - # The above only validates the result. Did we actually bypass rebase? - git reflog -1 >reflog.actual && -- sed "s/^[0-9a-f][0-9a-f]*/OBJID/" reflog.actual >reflog.fuzzy && -- echo "OBJID HEAD@{0}: pull --rebase . ff: Fast-forward" >reflog.expected && -+ sed -e "s/^[0-9a-f][0-9a-f]*/OBJID/" -e "s/[0-9a-f][0-9a-f]*$/OBJID/" reflog.actual >reflog.fuzzy && -+ echo "OBJID HEAD@{0}: rebase finished: refs/heads/to-rebase onto OBJID" >reflog.expected && - test_cmp reflog.expected reflog.fuzzy - ' - 5: 9b116f3d284 = 5: b242d001132 pull: make --rebase and --no-rebase override pull.ff=only 6: f061f8b4e75 = 6: 7447c719bd7 pull: abort by default when fast-forwarding is not possible 7: 90d49e0fb78 = 7: 726082f2e79 pull: update docs & code for option compatibility with rebasing 8: f03b15b7eb0 = 8: 768dec71558 pull: fix handling of multiple heads -- gitgitgadget
