[PATCH 3/3] builtins: check for startup_info->help, print and exit early

["Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>]

These commands need more than just git_config() before parsing
commmand line arguments. Some of these activities will unconditionally
look into a repository. When startup_info->help is TRUE, no repository
is set up and the caller expects callees to print help usage and exit,
no more.

Do as expected.
---
 builtin/branch.c         |    3 +++
 builtin/checkout-index.c |    3 +++
 builtin/commit.c         |    6 ++++++
 builtin/gc.c             |    3 +++
 builtin/ls-files.c       |    3 +++
 builtin/merge.c          |    3 +++
 builtin/update-index.c   |    3 +++
 builtin/upload-archive.c |    7 ++++---
 t/t3905-help.sh          |   20 ++++++++++++++++++++
 9 files changed, 48 insertions(+), 3 deletions(-)
 create mode 100755 t/t3905-help.sh

diff --git a/builtin/branch.c b/builtin/branch.c
index 87976f0..9f152ed 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -667,6 +667,9 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
 		OPT_END(),
 	};
 
+	if (startup_info->help)
+		usage_with_options(builtin_branch_usage, options);
+
 	git_config(git_branch_config, NULL);
 
 	if (branch_use_color == -1)
diff --git a/builtin/checkout-index.c b/builtin/checkout-index.c
index a7a5ee1..7f25cd7 100644
--- a/builtin/checkout-index.c
+++ b/builtin/checkout-index.c
@@ -241,6 +241,9 @@ int cmd_checkout_index(int argc, const char **argv, const char *prefix)
 		OPT_END()
 	};
 
+	if (startup_info->help)
+		usage_with_options(builtin_checkout_index_usage, builtin_checkout_index_options);
+
 	git_config(git_default_config, NULL);
 	state.base_dir = "";
 	prefix_length = prefix ? strlen(prefix) : 0;
diff --git a/builtin/commit.c b/builtin/commit.c
index 66fdd22..8b086f2 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -1070,6 +1070,9 @@ int cmd_status(int argc, const char **argv, const char *prefix)
 		OPT_END(),
 	};
 
+	if (startup_info->help)
+		usage_with_options(builtin_status_usage, builtin_status_options);
+
 	if (null_termination && status_format == STATUS_FORMAT_LONG)
 		status_format = STATUS_FORMAT_PORCELAIN;
 
@@ -1255,6 +1258,9 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 	int allow_fast_forward = 1;
 	struct wt_status s;
 
+	if (startup_info->help)
+		usage_with_options(builtin_commit_usage, builtin_commit_options);
+
 	wt_status_prepare(&s);
 	git_config(git_commit_config, &s);
 	in_merge = file_exists(git_path("MERGE_HEAD"));
diff --git a/builtin/gc.c b/builtin/gc.c
index c304638..f040171 100644
--- a/builtin/gc.c
+++ b/builtin/gc.c
@@ -191,6 +191,9 @@ int cmd_gc(int argc, const char **argv, const char *prefix)
 
 	git_config(gc_config, NULL);
 
+	if (startup_info->help)
+		usage_with_options(builtin_gc_usage, builtin_gc_options);
+
 	if (pack_refs < 0)
 		pack_refs = !is_bare_repository();
 
diff --git a/builtin/ls-files.c b/builtin/ls-files.c
index bb4f612..814da51 100644
--- a/builtin/ls-files.c
+++ b/builtin/ls-files.c
@@ -530,6 +530,9 @@ int cmd_ls_files(int argc, const char **argv, const char *cmd_prefix)
 		OPT_END()
 	};
 
+	if (startup_info->help)
+		usage_with_options(ls_files_usage, builtin_ls_files_options);
+
 	memset(&dir, 0, sizeof(dir));
 	prefix = cmd_prefix;
 	if (prefix)
diff --git a/builtin/merge.c b/builtin/merge.c
index 2dba3b9..0169694 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -917,6 +917,9 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 	const char *best_strategy = NULL, *wt_strategy = NULL;
 	struct commit_list **remotes = &remoteheads;
 
+	if (startup_info->help)
+		usage_with_options(builtin_merge_usage, builtin_merge_options);
+
 	if (read_cache_unmerged()) {
 		die_resolve_conflict("merge");
 	}
diff --git a/builtin/update-index.c b/builtin/update-index.c
index 3ab214d..46a53f5 100644
--- a/builtin/update-index.c
+++ b/builtin/update-index.c
@@ -589,6 +589,9 @@ int cmd_update_index(int argc, const char **argv, const char *prefix)
 	int lock_error = 0;
 	struct lock_file *lock_file;
 
+	if (startup_info->help)
+		usage(update_index_usage);
+
 	git_config(git_default_config, NULL);
 
 	/* We can't free this memory, it becomes part of a linked list parsed atexit() */
diff --git a/builtin/upload-archive.c b/builtin/upload-archive.c
index 73f788e..d4f4741 100644
--- a/builtin/upload-archive.c
+++ b/builtin/upload-archive.c
@@ -26,9 +26,6 @@ static int run_upload_archive(int argc, const char **argv, const char *prefix)
 	int sent_argc;
 	int len;
 
-	if (argc != 2)
-		usage(upload_archive_usage);
-
 	if (strlen(argv[1]) + 1 > sizeof(buf))
 		die("insanely long repository name");
 
@@ -98,6 +95,10 @@ int cmd_upload_archive(int argc, const char **argv, const char *prefix)
 {
 	pid_t writer;
 	int fd1[2], fd2[2];
+
+	if (startup_info->help || argc != 2)
+		usage(upload_archive_usage);
+
 	/*
 	 * Set up sideband subprocess.
 	 *
diff --git a/t/t3905-help.sh b/t/t3905-help.sh
new file mode 100755
index 0000000..c7e80c5
--- /dev/null
+++ b/t/t3905-help.sh
@@ -0,0 +1,20 @@
+#!/bin/sh
+
+test_description='tests that git foo -h should work even in broken repos'
+
+. ./test-lib.sh
+
+test_expect_success 'setup' '
+	git config core.repositoryformatversion 99 &&
+	test_must_fail git rev-parse HEAD
+'
+
+CMDS="branch checkout-index commit gc ls-files merge update-index upload-archive"
+for cmd in $CMDS; do
+	test_expect_success "$cmd -h" "
+		test_must_fail git $cmd -h &&
+		test \$exit_code = 129
+	"
+done
+
+test_done
-- 
1.7.0.2.445.gcbdb3