Merge branch 'js/alias-early-config' into maint

The code to pick up and execute command alias definition from the
configuration used to switch to the top of the working tree and
then come back when the expanded alias was executed, which was
unnecessarilyl complex.  Attempt to simplify the logic by using the
early-config mechanism that does not chdir around.

* js/alias-early-config:
  alias: use the early config machinery to expand aliases
  t7006: demonstrate a problem with aliases in subdirectories
  t1308: relax the test verifying that empty alias values are disallowed
  help: use early config when autocorrecting aliases
  config: report correct line number upon error
  discover_git_directory(): avoid setting invalid git_dir

8 files changed, 49 insertions, 61 deletions

diff --git a/alias.c b/alias.c
index 3b90397a99..0526304661 100644
--- a/alias.c
+++ b/alias.c
@@ -1,14 +1,28 @@
 #include "cache.h"
 
+struct config_alias_data {
+	const char *alias;
+	char *v;
+};
+
+static int config_alias_cb(const char *key, const char *value, void *d)
+{
+	struct config_alias_data *data = d;
+	const char *p;
+
+	if (skip_prefix(key, "alias.", &p) && !strcmp(p, data->alias))
+		return git_config_string((const char **)&data->v, key, value);
+
+	return 0;
+}
+
 char *alias_lookup(const char *alias)
 {
-	char *v = NULL;
-	struct strbuf key = STRBUF_INIT;
-	strbuf_addf(&key, "alias.%s", alias);
-	if (git_config_key_is_valid(key.buf))
-		git_config_get_string(key.buf, &v);
-	strbuf_release(&key);
-	return v;
+	struct config_alias_data data = { alias, NULL };
+
+	read_early_config(config_alias_cb, &data);
+
+	return data.v;
 }
 
 #define SPLIT_CMDLINE_BAD_ENDING 1
diff --git a/config.c b/config.c
index a30056ec7e..f0511e58e2 100644
--- a/config.c
+++ b/config.c
@@ -588,7 +588,8 @@ static int get_value(config_fn_t fn, void *data, struct strbuf *name)
 	 */
 	cf->linenr--;
 	ret = fn(name->buf, value, data);
-	cf->linenr++;
+	if (ret >= 0)
+		cf->linenr++;
 	return ret;
 }
 
diff --git a/git.c b/git.c
index 8ff44f081d..58ef570294 100644
--- a/git.c
+++ b/git.c
@@ -16,50 +16,6 @@ const char git_more_info_string[] =
 	   "to read about a specific subcommand or concept.");
 
 static int use_pager = -1;
-static char *orig_cwd;
-static const char *env_names[] = {
-	GIT_DIR_ENVIRONMENT,
-	GIT_WORK_TREE_ENVIRONMENT,
-	GIT_IMPLICIT_WORK_TREE_ENVIRONMENT,
-	GIT_PREFIX_ENVIRONMENT
-};
-static char *orig_env[4];
-static int save_restore_env_balance;
-
-static void save_env_before_alias(void)
-{
-	int i;
-
-	assert(save_restore_env_balance == 0);
-	save_restore_env_balance = 1;
-	orig_cwd = xgetcwd();
-	for (i = 0; i < ARRAY_SIZE(env_names); i++) {
-		orig_env[i] = getenv(env_names[i]);
-		orig_env[i] = xstrdup_or_null(orig_env[i]);
-	}
-}
-
-static void restore_env(int external_alias)
-{
-	int i;
-
-	assert(save_restore_env_balance == 1);
-	save_restore_env_balance = 0;
-	if (!external_alias && orig_cwd && chdir(orig_cwd))
-		die_errno("could not move to %s", orig_cwd);
-	free(orig_cwd);
-	for (i = 0; i < ARRAY_SIZE(env_names); i++) {
-		if (external_alias &&
-		    !strcmp(env_names[i], GIT_PREFIX_ENVIRONMENT))
-			continue;
-		if (orig_env[i]) {
-			setenv(env_names[i], orig_env[i], 1);
-			free(orig_env[i]);
-		} else {
-			unsetenv(env_names[i]);
-		}
-	}
-}
 
 static void commit_pager_choice(void) {
 	switch (use_pager) {
@@ -250,19 +206,18 @@ static int handle_alias(int *argcp, const char ***argv)
 	const char **new_argv;
 	const char *alias_command;
 	char *alias_string;
-	int unused_nongit;
-
-	save_env_before_alias();
-	setup_git_directory_gently(&unused_nongit);
 
 	alias_command = (*argv)[0];
 	alias_string = alias_lookup(alias_command);
 	if (alias_string) {
 		if (alias_string[0] == '!') {
 			struct child_process child = CHILD_PROCESS_INIT;
+			int nongit_ok;
+
+			/* Aliases expect GIT_PREFIX, GIT_DIR etc to be set */
+			setup_git_directory_gently(&nongit_ok);
 
 			commit_pager_choice();
-			restore_env(1);
 
 			child.use_shell = 1;
 			argv_array_push(&child.args, alias_string + 1);
@@ -308,8 +263,6 @@ static int handle_alias(int *argcp, const char ***argv)
 		ret = 1;
 	}
 
-	restore_env(0);
-
 	errno = saved_errno;
 
 	return ret;
diff --git a/help.c b/help.c
index db7f3d79a0..b44c55ec2d 100644
--- a/help.c
+++ b/help.c
@@ -289,7 +289,7 @@ const char *help_unknown_cmd(const char *cmd)
 	memset(&other_cmds, 0, sizeof(other_cmds));
 	memset(&aliases, 0, sizeof(aliases));
 
-	git_config(git_unknown_cmd_config, NULL);
+	read_early_config(git_unknown_cmd_config, NULL);
 
 	load_command_list("git-", &main_cmds, &other_cmds);
 
diff --git a/setup.c b/setup.c
index e3f7699a90..2435186e44 100644
--- a/setup.c
+++ b/setup.c
@@ -982,6 +982,7 @@ const char *discover_git_directory(struct strbuf *gitdir)
 		warning("ignoring git dir '%s': %s",
 			gitdir->buf + gitdir_offset, err.buf);
 		strbuf_release(&err);
+		strbuf_setlen(gitdir, gitdir_offset);
 		return NULL;
 	}
 
diff --git a/t/t1300-repo-config.sh b/t/t1300-repo-config.sh
index 13b7851f7c..a37ef04222 100755
--- a/t/t1300-repo-config.sh
+++ b/t/t1300-repo-config.sh
@@ -703,6 +703,12 @@ test_expect_success 'invalid unit' '
 	test_i18ngrep "bad numeric config value .1auto. for .aninvalid.unit. in file .git/config: invalid unit" actual
 '
 
+test_expect_success 'line number is reported correctly' '
+	printf "[bool]\n\tvar\n" >invalid &&
+	test_must_fail git config -f invalid --path bool.var 2>actual &&
+	test_i18ngrep "line 2" actual
+'
+
 test_expect_success 'invalid stdin config' '
 	echo "[broken" | test_must_fail git config --list --file - >output 2>&1 &&
 	test_i18ngrep "bad config line 1 in standard input" output
diff --git a/t/t1308-config-set.sh b/t/t1308-config-set.sh
index ff50960cca..69a0aa56d6 100755
--- a/t/t1308-config-set.sh
+++ b/t/t1308-config-set.sh
@@ -215,7 +215,9 @@ test_expect_success 'check line errors for malformed values' '
 		br
 	EOF
 	test_expect_code 128 git br 2>result &&
-	test_i18ngrep "fatal: .*alias\.br.*\.git/config.*line 2" result
+	test_i18ngrep "missing value for .alias\.br" result &&
+	test_i18ngrep "fatal: .*\.git/config" result &&
+	test_i18ngrep "fatal: .*line 2" result
 '
 
 test_expect_success 'error on modifying repo config without repo' '
diff --git a/t/t7006-pager.sh b/t/t7006-pager.sh
index 4f3794d415..20b4d83c28 100755
--- a/t/t7006-pager.sh
+++ b/t/t7006-pager.sh
@@ -391,6 +391,17 @@ test_expect_success TTY 'core.pager in repo config works and retains cwd' '
 	)
 '
 
+test_expect_success TTY 'core.pager is found via alias in subdirectory' '
+	sane_unset GIT_PAGER &&
+	test_config core.pager "cat >via-alias" &&
+	(
+		cd sub &&
+		rm -f via-alias &&
+		test_terminal git -c alias.r="-p rev-parse" r HEAD &&
+		test_path_is_file via-alias
+	)
+'
+
 test_doesnt_paginate      expect_failure test_must_fail 'git -p nonsense'
 
 test_pager_choices                       'git shortlog'