It is very typical for Git newcomers to inadvertently create merges and worse; pushing them. This is one of the reasons many experienced users prefer to avoid 'git pull', and recommend newcomers to avoid it as well. To escape these problems--and keep 'git pull' useful--it has been suggested that 'git pull' barfs by default if the merge is non-fast-forward, which unfortunately would break backwards compatibility. This patch leaves everything in place to enable this new mode, but it only gets enabled if the user specifically configures it: pull.mode = fast-forward Later on this mode can be enabled by default. For *some* of the long discussions you can read: https://lore.kernel.org/git/742df4c2-2bc5-8a4b-8de1-cd5e48718398@xxxxxxxxxx/ https://lore.kernel.org/git/20130522115042.GA20649@xxxxxxxxxxxxxx https://lore.kernel.org/git/1377988690-23460-1-git-send-email-felipe.contreras@xxxxxxxxx https://lore.kernel.org/git/4ay6w9i74cygt6ii1b0db7wg.1398433713382@xxxxxxxxxxxxxxxxx Signed-off-by: Felipe Contreras <felipe.contreras@xxxxxxxxx> --- Documentation/config/branch.txt | 4 +-- Documentation/config/pull.txt | 4 +-- builtin/pull.c | 6 ++++- rebase.c | 2 ++ rebase.h | 3 ++- t/t5520-pull.sh | 44 +++++++++++++++++++++++++++++++++ 6 files changed, 57 insertions(+), 6 deletions(-) diff --git a/Documentation/config/branch.txt b/Documentation/config/branch.txt index 5f412caf62..a61c80c90b 100644 --- a/Documentation/config/branch.txt +++ b/Documentation/config/branch.txt @@ -103,8 +103,8 @@ branch.<name>.updateMode:: branch.<name>.pullMode:: When `git pull` is run, this determines the mode of operation, - possible values are 'merge' and 'rebase'. See `pull.mode` for doing this - in a non branch-specific manner. + possible values are 'fast-forward', 'merge', and 'rebase'. + See `pull.mode` for doing this in a non branch-specific manner. branch.<name>.description:: Branch description, can be edited with diff --git a/Documentation/config/pull.txt b/Documentation/config/pull.txt index 3fb9bfdfea..7b3dddf4d4 100644 --- a/Documentation/config/pull.txt +++ b/Documentation/config/pull.txt @@ -32,8 +32,8 @@ for details). pull.mode:: When "git pull" is run, this determines if it would either merge or rebase the fetched branch. The possible values are 'merge', - and 'rebase'. See "branch.<name>.pullMode" for setting this on a - per-branch basis. + 'rebase', and 'fast-forward'. See "branch.<name>.pullMode" for setting + this on a per-branch basis. pull.octopus:: The default merge strategy to use when pulling multiple branches diff --git a/builtin/pull.c b/builtin/pull.c index bb3c0b55f9..295c13fbe8 100644 --- a/builtin/pull.c +++ b/builtin/pull.c @@ -979,7 +979,7 @@ static void show_advice_pull_non_ff(void) "\n" " git config pull.mode merge # the default strategy\n" " git config pull.mode rebase\n" - " git config pull.ff only # fast-forward only\n" + " git config pull.mode fast-forward\n" "\n" "You can replace \"git config\" with \"git config --global\" to set a default\n" "preference for all repositories. You can also pass --rebase, --merge,\n" @@ -1023,6 +1023,7 @@ int cmd_pull(int argc, const char **argv, const char *prefix) switch (mode) { case PULL_MODE_MERGE: + case PULL_MODE_FAST_FORWARD: opt_rebase = REBASE_FALSE; break; case PULL_MODE_REBASE: @@ -1113,6 +1114,9 @@ int cmd_pull(int argc, const char **argv, const char *prefix) can_ff = get_can_ff(&orig_head, &merge_heads.oid[0]); + if (mode == PULL_MODE_FAST_FORWARD && !can_ff) + die(_("The pull was not fast-forward, either merge or rebase.\n")); + if (!opt_rebase && !can_ff) { if (opt_verbosity >= 0) show_advice_pull_non_ff(); diff --git a/rebase.c b/rebase.c index bdfca49886..9fe99b5b16 100644 --- a/rebase.c +++ b/rebase.c @@ -40,6 +40,8 @@ enum pull_mode_type pull_mode_parse_value(const char *value) return PULL_MODE_MERGE; else if (!strcmp(value, "rebase") || !strcmp(value, "r")) return PULL_MODE_REBASE; + else if (!strcmp(value, "fast-forward") || !strcmp(value, "f")) + return PULL_MODE_FAST_FORWARD; return PULL_MODE_INVALID; } diff --git a/rebase.h b/rebase.h index 5ab8f4ddd5..e66a73feb4 100644 --- a/rebase.h +++ b/rebase.h @@ -17,7 +17,8 @@ enum pull_mode_type { PULL_MODE_INVALID = -1, PULL_MODE_DEFAULT = 0, PULL_MODE_MERGE, - PULL_MODE_REBASE + PULL_MODE_REBASE, + PULL_MODE_FAST_FORWARD }; enum pull_mode_type pull_mode_parse_value(const char *value); diff --git a/t/t5520-pull.sh b/t/t5520-pull.sh index 59894dd15a..7ea558651d 100755 --- a/t/t5520-pull.sh +++ b/t/t5520-pull.sh @@ -869,4 +869,48 @@ test_expect_success 'git pull --rebase against local branch' ' test_cmp expect file2 ' +setup_other () { + test_when_finished "git checkout main && git branch -D other test" && + git checkout -b other $1 && + >new && + git add new && + git commit -m new && + git checkout -b test -t other && + git reset --hard main +} + +setup_ff () { + setup_other main +} + +setup_non_ff () { + setup_other main^ +} + +test_expect_success 'fast-forward (pull.mode=fast-forward)' ' + setup_ff && + git -c pull.mode=fast-forward pull +' + +test_expect_success 'non-fast-forward (pull.mode=fast-forward)' ' + setup_non_ff && + test_must_fail git -c pull.mode=fast-forward pull +' + +test_expect_success 'non-fast-forward with merge (pull.mode=fast-forward)' ' + setup_non_ff && + git -c pull.mode=fast-forward pull --merge +' + +test_expect_success 'non-fast-forward with rebase (pull.mode=fast-forward)' ' + setup_non_ff && + git -c pull.mode=fast-forward pull --rebase +' + +test_expect_success 'non-fast-forward error message (pull.mode=fast-forward)' ' + setup_non_ff && + test_must_fail git -c pull.mode=fast-forward pull 2> error && + test_i18ngrep "The pull was not fast-forward" error +' + test_done -- 2.32.0.36.g70aac2b1aa
