diff --git a/Documentation/config/diff.txt b/Documentation/config/diff.txt index 5ce7b91f1d..190bda17e5 100644 --- a/Documentation/config/diff.txt +++ b/Documentation/config/diff.txt @@ -79,6 +79,15 @@ diff.external:: you want to use an external diff program only on a subset of your files, you might want to use linkgit:gitattributes[5] instead. +diff.trustExitCode:: + If this boolean value is set to true then the + `diff.external` command is expected to return exit code + 0 if it considers the input files to be equal or 1 if it + considers them to be different, like `diff(1)`. + If it is set to false, which is the default, then the command + is expected to return exit code 0 regardless of equality. + Any other exit code causes Git to report a fatal error. + diff.ignoreSubmodules:: Sets the default value of --ignore-submodules. Note that this affects only 'git diff' Porcelain, and not lower level 'diff' @@ -164,6 +173,15 @@ diff..command:: The custom diff driver command. See linkgit:gitattributes[5] for details. +diff..trustExitCode:: + If this boolean value is set to true then the + `diff..command` command is expected to return exit code + 0 if it considers the input files to be equal or 1 if it + considers them to be different, like `diff(1)`. + If it is set to false, which is the default, then the command + is expected to return exit code 0 regardless of equality. + Any other exit code causes Git to report a fatal error. + diff..xfuncname:: The regular expression that the diff driver should use to recognize the hunk header. A built-in pattern may also be used. diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt index c7df20e571..cd0b81adbb 100644 --- a/Documentation/diff-options.txt +++ b/Documentation/diff-options.txt @@ -820,6 +820,11 @@ ifndef::git-log[] --quiet:: Disable all output of the program. Implies `--exit-code`. + Disables execution of external diff helpers whose exit code + is not trusted, i.e. their respective configuration option + `diff.trustExitCode` or `diff..trustExitCode` or + environment variable `GIT_EXTERNAL_DIFF_TRUST_EXIT_CODE` is + false. endif::git-log[] endif::git-format-patch[] diff --git a/Documentation/git.txt b/Documentation/git.txt index a31a70acca..4489e2297a 100644 --- a/Documentation/git.txt +++ b/Documentation/git.txt @@ -644,6 +644,16 @@ parameter, . For each path `GIT_EXTERNAL_DIFF` is called, two environment variables, `GIT_DIFF_PATH_COUNTER` and `GIT_DIFF_PATH_TOTAL` are set. +`GIT_EXTERNAL_DIFF_TRUST_EXIT_CODE`:: + If this Boolean environment variable is set to true then the + `GIT_EXTERNAL_DIFF` command is expected to return exit code + 0 if it considers the input files to be equal or 1 if it + considers them to be different, like `diff(1)`. + If it is set to false, which is the default, then the command + is expected to return exit code 0 regardless of equality. + Any other exit code causes Git to report a fatal error. + + `GIT_DIFF_PATH_COUNTER`:: A 1-based counter incremented by one for every path. diff --git a/Documentation/gitattributes.txt b/Documentation/gitattributes.txt index 4338d023d9..80cae17f37 100644 --- a/Documentation/gitattributes.txt +++ b/Documentation/gitattributes.txt @@ -776,6 +776,11 @@ with the above configuration, i.e. `j-c-diff`, with 7 parameters, just like `GIT_EXTERNAL_DIFF` program is called. See linkgit:git[1] for details. +If the program is able to ignore certain changes (similar to +`git diff --ignore-space-change`), then also set the option +`trustExitCode` to true. It is then expected to return exit code 1 if +it finds significant changes and 0 if it doesn't. + Setting the internal diff algorithm ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/diff.c b/diff.c index cecda216cf..6e432cb8fc 100644 --- a/diff.c +++ b/diff.c @@ -57,7 +57,7 @@ static int diff_color_moved_ws_default; static int diff_context_default = 3; static int diff_interhunk_context_default; static char *diff_word_regex_cfg; -static char *external_diff_cmd_cfg; +static struct external_diff external_diff_cfg; static char *diff_order_file_cfg; int diff_auto_refresh_index = 1; static int diff_mnemonic_prefix; @@ -431,7 +431,11 @@ int git_diff_ui_config(const char *var, const char *value, return 0; } if (!strcmp(var, "diff.external")) - return git_config_string(&external_diff_cmd_cfg, var, value); + return git_config_string(&external_diff_cfg.cmd, var, value); + if (!strcmp(var, "diff.trustexitcode")) { + external_diff_cfg.trust_exit_code = git_config_bool(var, value); + return 0; + } if (!strcmp(var, "diff.wordregex")) return git_config_string(&diff_word_regex_cfg, var, value); if (!strcmp(var, "diff.orderfile")) @@ -548,18 +552,22 @@ static char *quote_two(const char *one, const char *two) return strbuf_detach(&res, NULL); } -static const char *external_diff(void) +static const struct external_diff *external_diff(void) { - static const char *external_diff_cmd = NULL; + static struct external_diff external_diff_env, *external_diff_ptr; static int done_preparing = 0; if (done_preparing) - return external_diff_cmd; - external_diff_cmd = xstrdup_or_null(getenv("GIT_EXTERNAL_DIFF")); - if (!external_diff_cmd) - external_diff_cmd = external_diff_cmd_cfg; + return external_diff_ptr; + external_diff_env.cmd = xstrdup_or_null(getenv("GIT_EXTERNAL_DIFF")); + if (git_env_bool("GIT_EXTERNAL_DIFF_TRUST_EXIT_CODE", 0)) + external_diff_env.trust_exit_code = 1; + if (external_diff_env.cmd) + external_diff_ptr = &external_diff_env; + else if (external_diff_cfg.cmd) + external_diff_ptr = &external_diff_cfg; done_preparing = 1; - return external_diff_cmd; + return external_diff_ptr; } /* @@ -4375,7 +4383,7 @@ static void add_external_diff_name(struct repository *r, * infile2 infile2-sha1 infile2-mode [ rename-to ] * */ -static void run_external_diff(const char *pgm, +static void run_external_diff(const struct external_diff *pgm, const char *name, const char *other, struct diff_filespec *one, @@ -4385,8 +4393,21 @@ static void run_external_diff(const char *pgm, { struct child_process cmd = CHILD_PROCESS_INIT; struct diff_queue_struct *q = &diff_queued_diff; + int quiet = !(o->output_format & DIFF_FORMAT_PATCH); + int rc; - strvec_push(&cmd.args, pgm); + /* + * Trivial equality is handled by diff_unmodified_pair() before + * we get here. If we don't need to show the diff and the + * external diff program lacks the ability to tell us whether + * it's empty then we consider it non-empty without even asking. + */ + if (!pgm->trust_exit_code && quiet) { + o->found_changes = 1; + return; + } + + strvec_push(&cmd.args, pgm->cmd); strvec_push(&cmd.args, name); if (one && two) { @@ -4406,7 +4427,15 @@ static void run_external_diff(const char *pgm, diff_free_filespec_data(one); diff_free_filespec_data(two); cmd.use_shell = 1; - if (run_command(&cmd)) + cmd.no_stdout = quiet; + rc = run_command(&cmd); + if (!pgm->trust_exit_code && rc == 0) + o->found_changes = 1; + else if (pgm->trust_exit_code && rc == 0) + ; /* nothing */ + else if (pgm->trust_exit_code && rc == 1) + o->found_changes = 1; + else die(_("external diff died, stopping at %s"), name); remove_tempfile(); @@ -4512,7 +4541,7 @@ static void fill_metainfo(struct strbuf *msg, } } -static void run_diff_cmd(const char *pgm, +static void run_diff_cmd(const struct external_diff *pgm, const char *name, const char *other, const char *attr_path, @@ -4530,8 +4559,8 @@ static void run_diff_cmd(const char *pgm, if (o->flags.allow_external || !o->ignore_driver_algorithm) drv = userdiff_find_by_path(o->repo->index, attr_path); - if (o->flags.allow_external && drv && drv->external) - pgm = drv->external; + if (o->flags.allow_external && drv && drv->external.cmd) + pgm = &drv->external; if (msg) { /* @@ -4597,7 +4626,7 @@ static void strip_prefix(int prefix_length, const char **namep, const char **oth static void run_diff(struct diff_filepair *p, struct diff_options *o) { - const char *pgm = external_diff(); + const struct external_diff *pgm = external_diff(); struct strbuf msg; struct diff_filespec *one = p->one; struct diff_filespec *two = p->two; @@ -4924,6 +4953,13 @@ void diff_setup_done(struct diff_options *options) options->flags.exit_with_status = 1; } + /* + * External diffs could declare non-identical contents equal + * (think diff --ignore-space-change). + */ + if (options->flags.allow_external && options->flags.exit_with_status) + options->flags.diff_from_contents = 1; + options->diff_path_counter = 0; if (options->flags.follow_renames) diff --git a/t/t4020-diff-external.sh b/t/t4020-diff-external.sh index fdd865f7c3..3baa52a9bf 100755 --- a/t/t4020-diff-external.sh +++ b/t/t4020-diff-external.sh @@ -172,6 +172,72 @@ test_expect_success 'no diff with -diff' ' grep Binary out ' +check_external_diff () { + expect_code=$1 + expect_out=$2 + expect_err=$3 + command_code=$4 + trust_exit_code=$5 + shift 5 + options="$@" + + command="echo output; exit $command_code;" + desc="external diff '$command' with trustExitCode=$trust_exit_code" + with_options="${options:+ with }$options" + + test_expect_success "$desc via attribute$with_options" " + test_config diff.foo.command \"$command\" && + test_config diff.foo.trustExitCode $trust_exit_code && + echo \"file diff=foo\" >.gitattributes && + test_expect_code $expect_code git diff $options >out 2>err && + test_cmp $expect_out out && + test_cmp $expect_err err + " + + test_expect_success "$desc via diff.external$with_options" " + test_config diff.external \"$command\" && + test_config diff.trustExitCode $trust_exit_code && + >.gitattributes && + test_expect_code $expect_code git diff $options >out 2>err && + test_cmp $expect_out out && + test_cmp $expect_err err + " + + test_expect_success "$desc via GIT_EXTERNAL_DIFF$with_options" " + >.gitattributes && + test_expect_code $expect_code env \ + GIT_EXTERNAL_DIFF=\"$command\" \ + GIT_EXTERNAL_DIFF_TRUST_EXIT_CODE=$trust_exit_code \ + git diff $options >out 2>err && + test_cmp $expect_out out && + test_cmp $expect_err err + " +} + +test_expect_success 'setup output files' ' + : >empty && + echo output >output && + echo "fatal: external diff died, stopping at file" >error +' + +check_external_diff 0 output empty 0 off +check_external_diff 128 output error 1 off +check_external_diff 0 output empty 0 on +check_external_diff 0 output empty 1 on +check_external_diff 128 output error 2 on + +check_external_diff 1 output empty 0 off --exit-code +check_external_diff 128 output error 1 off --exit-code +check_external_diff 0 output empty 0 on --exit-code +check_external_diff 1 output empty 1 on --exit-code +check_external_diff 128 output error 2 on --exit-code + +check_external_diff 1 empty empty 0 off --quiet +check_external_diff 1 empty empty 1 off --quiet # we don't even call the program +check_external_diff 0 empty empty 0 on --quiet +check_external_diff 1 empty empty 1 on --quiet +check_external_diff 128 empty error 2 on --quiet + echo NULZbetweenZwords | perl -pe 'y/Z/\000/' > file test_expect_success 'force diff with "diff"' ' diff --git a/userdiff.c b/userdiff.c index 371032a413..c4ebb9ff73 100644 --- a/userdiff.c +++ b/userdiff.c @@ -333,7 +333,7 @@ PATTERNS("scheme", "|([^][)(}{[ \t])+"), PATTERNS("tex", "^(\\\\((sub)*section|chapter|part)\\*{0,1}\\{.*)$", "\\\\[a-zA-Z@]+|\\\\.|([a-zA-Z0-9]|[^\x01-\x7f])+"), -{ "default", NULL, NULL, -1, { NULL, 0 } }, +{ .name = "default", .binary = -1 }, }; #undef PATTERNS #undef IPATTERN @@ -445,7 +445,11 @@ int userdiff_config(const char *k, const char *v) if (!strcmp(type, "binary")) return parse_tristate(&drv->binary, k, v); if (!strcmp(type, "command")) - return git_config_string((char **) &drv->external, k, v); + return git_config_string((char **) &drv->external.cmd, k, v); + if (!strcmp(type, "trustexitcode")) { + drv->external.trust_exit_code = git_config_bool(k, v); + return 0; + } if (!strcmp(type, "textconv")) return git_config_string((char **) &drv->textconv, k, v); if (!strcmp(type, "cachetextconv")) diff --git a/userdiff.h b/userdiff.h index d726804c3e..7565930337 100644 --- a/userdiff.h +++ b/userdiff.h @@ -11,9 +11,14 @@ struct userdiff_funcname { int cflags; }; +struct external_diff { + char *cmd; + unsigned trust_exit_code:1; +}; + struct userdiff_driver { const char *name; - const char *external; + struct external_diff external; const char *algorithm; int binary; struct userdiff_funcname funcname;