log: improve --follow following renames for non-linear history

index f20cc25cd7..757a7be196 100644 --- a/Documentation/config/log.adoc +++ b/Documentation/config/log.adoc @@ -53,8 +53,7 @@ This is the same as the `--decorate` option of the `git log`. `log.follow`:: If `true`, `git log` will act as if the `--follow` option was used when a single <path> is given. This has the same limitations as `--follow`, - i.e. it cannot be used to follow multiple files and does not work well - on non-linear history. + i.e. it cannot be used to follow multiple files. `log.graphColors`:: A list of colors, separated by commas, that can be used to draw

index 88b3019293..83a3c4bf9b 100644 --- a/log-tree.c +++ b/log-tree.c @@ -3,6 +3,7 @@ #include "git-compat-util.h" #include "commit-reach.h" +#include "commit-slab.h" #include "config.h" #include "diff.h" #include "diffcore.h" @@ -1089,6 +1090,96 @@ static int do_remerge_diff(struct rev_info *opt, return !opt->loginfo; } +/* Per-commit path storage for --follow across merges */ +define_commit_slab(follow_pathspec_slab, char *); + +static const char *pathspec_single_path(const struct pathspec *ps) +{ + if (ps->nr != 1) + return NULL; + return ps->items[0].match; +} + +static void set_pathspec_to_single_path(struct pathspec *ps, const char *path) +{ + const char *paths[2] = { path, NULL }; + + clear_pathspec(ps); + parse_pathspec(ps, + PATHSPEC_ALL_MAGIC & ~PATHSPEC_LITERAL, + PATHSPEC_LITERAL_PATH, "", paths); +} + +static void remember_follow_pathspec(struct rev_info *opt, + struct commit *c, const char *path) +{ + char **slot; + + if (!path) + return; + if (!opt->follow_pathspec_slab) { + opt->follow_pathspec_slab = xmalloc(sizeof(*opt->follow_pathspec_slab)); + init_follow_pathspec_slab(opt->follow_pathspec_slab); + } + slot = follow_pathspec_slab_at(opt->follow_pathspec_slab, c); + if (*slot && !strcmp(*slot, path)) + return; + free(*slot); + *slot = xstrdup(path); +} + +static const char *recall_follow_pathspec(struct rev_info *opt, + struct commit *c) +{ + char **slot; + + if (!opt->follow_pathspec_slab) + return NULL; + slot = follow_pathspec_slab_peek(opt->follow_pathspec_slab, c); + return slot ? *slot : NULL; +} + +static void free_follow_pathspec_slot(char **slot) +{ + FREE_AND_NULL(*slot); +} + +void release_follow_pathspec_slab(struct rev_info *opt) +{ + if (!opt->follow_pathspec_slab) + return; + deep_clear_follow_pathspec_slab(opt->follow_pathspec_slab, + free_follow_pathspec_slot); + FREE_AND_NULL(opt->follow_pathspec_slab); +} + +/* Compute a path to follow in parent, if there is one */ +static void propagate_follow_pathspec_to_parent(struct rev_info *opt, + struct commit *commit, + struct commit *parent) +{ + struct diff_options diff_opts; + const char *path; + + parse_commit_or_die(parent); + repo_diff_setup(opt->diffopt.repo, &diff_opts); + copy_pathspec(&diff_opts.pathspec, &opt->diffopt.pathspec); + diff_opts.flags.recursive = 1; + diff_opts.flags.follow_renames = 1; + diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT; + diff_setup_done(&diff_opts); + diff_tree_oid(get_commit_tree_oid(parent), + get_commit_tree_oid(commit), + "", &diff_opts); + + path = pathspec_single_path(&diff_opts.pathspec); + if (path) + remember_follow_pathspec(opt, parent, path); + + diff_queue_clear(&diff_queued_diff); + diff_free(&diff_opts); +} + /* * Show the diff of a commit. * @@ -1185,6 +1276,16 @@ int log_tree_commit(struct rev_info *opt, struct commit *commit) opt->loginfo = &log; opt->diffopt.no_free = 1; + /* Any recorded path for this commit? If so, restore it */ + if (opt->diffopt.flags.follow_renames) { + const char *stored = recall_follow_pathspec(opt, commit); + if (stored) { + const char *current = pathspec_single_path(&opt->diffopt.pathspec); + if (!current || strcmp(current, stored)) + set_pathspec_to_single_path(&opt->diffopt.pathspec, stored); + } + } + if (opt->track_linear && !opt->linear && !opt->reverse_output_stage) fprintf(opt->diffopt.file, "\n%s\n", opt->break_bar); shown = log_tree_diff(opt, commit, &log); @@ -1197,6 +1298,21 @@ int log_tree_commit(struct rev_info *opt, struct commit *commit) fprintf(opt->diffopt.file, "\n%s\n", opt->break_bar); if (shown) show_diff_of_diff(opt); + + /* Record what path each parent of this commit should use */ + if (opt->diffopt.flags.follow_renames) { + struct commit_list *parents = get_saved_parents(opt, commit); + if (parents && parents->next) { + struct commit_list *p; + for (p = parents; p; p = p->next) + propagate_follow_pathspec_to_parent(opt, commit, + p->item); + } else if (parents) { + remember_follow_pathspec(opt, parents->item, + pathspec_single_path(&opt->diffopt.pathspec)); + } + } + opt->loginfo = NULL; maybe_flush_or_die(opt->diffopt.file, "stdout"); opt->diffopt.no_free = no_free;

index 07924be8bc..e8679b6c4a 100644 --- a/log-tree.h +++ b/log-tree.h @@ -26,6 +26,7 @@ struct decoration_options { int parse_decorate_color_config(const char *var, const char *slot_name, const char *value); int log_tree_diff_flush(struct rev_info *); int log_tree_commit(struct rev_info *, struct commit *); +void release_follow_pathspec_slab(struct rev_info *); void show_log(struct rev_info *opt); void format_decorations(struct strbuf *sb, const struct commit *commit, enum git_colorbool use_color, const struct decoration_options *opts);

index e91d7e1f11..0c95edef59 100644 --- a/revision.c +++ b/revision.c @@ -26,6 +26,7 @@ #include "decorate.h" #include "string-list.h" #include "line-log.h" +#include "log-tree.h" #include "mailmap.h" #include "commit-slab.h" #include "cache-tree.h" @@ -3304,6 +3305,7 @@ void release_revisions(struct rev_info *revs) line_log_free(revs); oidset_clear(&revs->missing_commits); release_revisions_bloom_keyvecs(revs); + release_follow_pathspec_slab(revs); } static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)

index 00c392be37..569b3fa1cb 100644 --- a/revision.h +++ b/revision.h @@ -66,6 +66,7 @@ struct repository; struct rev_info; struct string_list; struct saved_parents; +struct follow_pathspec_slab; struct bloom_keyvec; struct bloom_filter_settings; struct option; @@ -363,6 +364,9 @@ struct rev_info { /* copies of the parent lists, for --full-diff display */ struct saved_parents *saved_parents_slab; + /* per-commit pathspec for --follow across merges */ + struct follow_pathspec_slab *follow_pathspec_slab; + struct commit_list *previous_parents; struct commit_list *ancestry_path_bottoms; const char *break_bar;

index 3219264fe7..b6ac49b443 100644 --- a/t/meson.build +++ b/t/meson.build @@ -576,6 +576,7 @@ integration_tests = [ 't4215-log-skewed-merges.sh', 't4216-log-bloom.sh', 't4217-log-limit.sh', + 't4219-log-follow-merge.sh', 't4252-am-options.sh', 't4253-am-keep-cr-dos.sh', 't4254-am-corrupt.sh',

new file mode 100755 index 0000000000..e370f82955 --- /dev/null +++ b/t/t4219-log-follow-merge.sh @@ -0,0 +1,129 @@ +#!/bin/sh + +test_description='Test --follow follows renames across merges' + +GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=master +export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME + +. ./test-lib.sh + +test_expect_success 'setup subtree-merged repository' ' + git init inner && + echo inner >inner/inner.txt && + git -C inner add inner.txt && + git -C inner commit -m "inner init" && + + git init outer && + echo outer >outer/outer.txt && + git -C outer add outer.txt && + git -C outer commit -m "outer init" && + + git -C outer fetch ../inner master && + git -C outer merge -s ours --no-commit --allow-unrelated-histories \ + FETCH_HEAD && + git -C outer read-tree --prefix=inner/ -u FETCH_HEAD && + git -C outer commit -m "Merge inner repo into inner/ subdirectory" +' + +test_expect_success '--follow finds the pre-merge commit through a subtree merge' ' + git -C outer log --follow --pretty=tformat:%s inner/inner.txt >actual && + echo "inner init" >expect && + test_cmp expect actual +' + +test_expect_success 'setup merge of two branches that both renamed a file to README' ' + git init foo && + mkdir foo/foo && + echo "foo readme" >foo/foo/README && + git -C foo add foo/README && + git -C foo commit -m "add foo README" && + + git -C foo mv foo/README README && + git -C foo commit -m "promote foo README to toplevel" && + + echo "foo c" >foo/foo.c && + git -C foo add foo.c && + git -C foo commit -m "add foo C impl" && + + git init bar && + mkdir bar/bar && + echo "bar readme" >bar/bar/README && + git -C bar add bar/README && + git -C bar commit -m "add bar README" && + + git -C bar mv bar/README README && + git -C bar commit -m "promote bar README to toplevel" && + + echo "bar c" >bar/bar.c && + git -C bar add bar.c && + git -C bar commit -m "add bar C impl" && + + git -C foo fetch ../bar master && + git -C foo merge -s ours --no-commit --allow-unrelated-histories \ + FETCH_HEAD && + git -C foo checkout FETCH_HEAD -- bar.c && + git -C foo commit -m "merge bar into foo" +' + +test_expect_success '--follow follows renames across both sides of a merge' ' + git -C foo log --follow --pretty=tformat:%s README >actual && + sort actual >actual.sorted && + cat >expect <<-\EOF && + add bar README + add foo README + promote bar README to toplevel + promote foo README to toplevel + EOF + test_cmp expect actual.sorted +' + +test_expect_success 'setup diamond with renames on both sides of a fork' ' + git init diamond && + test_lines="line 1\nline 2\nline 3\nline 4\nline 5\n" && + + printf "$test_lines" >diamond/path0 && + git -C diamond add path0 && + git -C diamond commit -m "A: add path0" && + + git -C diamond checkout -b upper && + printf "line 1\nline 2\nline 3 modified by B\nline 4\nline 5\n" \ + >diamond/path0 && + git -C diamond commit -am "B: modify path0 on upper" && + git -C diamond mv path0 path1 && + git -C diamond commit -m "X: rename path0 to path1" && + + git -C diamond checkout -b lower master && + printf "line 1\nline 2\nline 3 modified by C\nline 4\nline 5\n" \ + >diamond/path0 && + git -C diamond commit -am "C: modify path0 on lower" && + git -C diamond mv path0 path2 && + git -C diamond commit -m "Y: rename path0 to path2" && + + git -C diamond checkout upper && + git -C diamond merge -s ours --no-commit lower && + git -C diamond rm path1 && + printf "line 1\nline 2\nline 3 merged\nline 4\nline 5\n" \ + >diamond/path && + git -C diamond add path && + git -C diamond commit -m "M: merge with rename to path" && + + printf "line 1\nline 2\nline 3 merged again\nline 4\nline 5\n" \ + >diamond/path && + git -C diamond commit -am "Z: modify path" +' + +test_expect_success '--follow follows renames through a fork in a single history' ' + git -C diamond log --follow --pretty=tformat:%s path >actual && + sort actual >actual.sorted && + cat >expect <<-\EOF && + A: add path0 + B: modify path0 on upper + C: modify path0 on lower + X: rename path0 to path1 + Y: rename path0 to path2 + Z: modify path + EOF + test_cmp expect actual.sorted +' + +test_done