git.c: fix, stop passing options after --help

From: Daniel Sonbolian <[email protected]>

Since commit c6b6d9f7d8a when passing --help option to a Git command, we try to open that command man page, we do it for both commands and concepts, it is done by converting the entered command to a help command for the given Git command, for example:

"git commit --help -i" into "git help --exclude-guides commit -i"

But the options after --help option are also passed to the new command (-i option from the example) which can lead to unexpected output, because the help command will try to execute those extra options.

This fixed by building the argv statically, meaning instead of switching places between argv arguments and then passing all the arguments to a new memory vector that will later be used as the new argv, we directly passing that memory vector only the required arguments and in the correct order, after that we also updating the argc to a static number:

	strvec_push(&args, "help");  // argv[0]
	strvec_push(&args, "--exclude-guides");  // argv[1]
	strvec_push(&args, argv[0]);  // argv[2]
	argv = args.v;
	argc = 3;  // update based on the amount of pushs we did

Now no matter how many arguments we pass after the --help, the results will always stay the same:

	"git commit --help foo-hello-world"
	"git commit --help pull -i -f"
	"git commit --help -i"
	|
	v
	"git help --exclude-guides commit"

---
git.c: fix, passing options after --help

Since commit c6b6d9f7d8a when passing --help option to a Git command, we try to open that command man page, we do it for both commands and concepts, it is done by converting the entered command to a help command for the given Git command, for example:

"git commit --help -i" into "git help --exclude-guides commit -i"

But the options after --help option are also passed to the new command (-i option from the example) which can lead to unexpected output, because the help command will try to execute those extra options.

This fixed by building the argv statically, meaning instead of switching places between argv arguments and then passing all the arguments to a new memory vector that will later be used as the new argv, we directly passing that memory vector only the required arguments and in the correct order, after that we also updating the argc to a static number:

strvec_push(&args, "help"); // argv[0] strvec_push(&args, "--exclude-guides"); // argv[1] strvec_push(&args, argv[0]); // argv[2]
argv = args.v;
argc = 3; // update based on the amount of pushs we did

Now no matter how many arguments we pass after the --help, the results will always stay the same:

"git commit --help foo-hello-world"
"git commit --help pull -i -f"
"git commit --help -i"
|
v
"git help --exclude-guides commit"

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-1357%2Fdsal3389%2Fcmd-help-tweaks-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-1357/dsal3389/cmd-help-tweaks-v1
Pull-Request: https://github.com/git/git/pull/1357

 git.c | 18 ++++++------------
 1 file changed, 6 insertions(+), 12 deletions(-)

index da411c53822..75dcefa534d 100644
@@ -697,25 +697,19 @@ static void handle_builtin(int argc, const char **argv)
 	struct cmd_struct *builtin;
 
 	strip_extension(argv);
-	cmd = argv[0];
 
 	/* Turn "git cmd --help" into "git help --exclude-guides cmd" */
 	if (argc > 1 && !strcmp(argv[1], "--help")) {
-		int i;
-
-		argv[1] = argv[0];
-		argv[0] = cmd = "help";
-
-		for (i = 0; i < argc; i++) {
-			strvec_push(&args, argv[i]);
-			if (!i)
-				strvec_push(&args, "--exclude-guides");
-		}
+		strvec_push(&args, "help");
+		strvec_push(&args, "--exclude-guides");
+		strvec_push(&args, argv[0]);
 
-		argc++;
 		argv = args.v;
+		argc = 3;
 	}
 
+	cmd = argv[0];
+
 	builtin = get_builtin(cmd);
 	if (builtin)
 		exit(run_builtin(builtin, argc, argv));

base-commit: 3dcec76d9df911ed8321007b1d197c1a206dc164

gitgitgadget

When referring to an old work, use

    $(git show -s --pretty=reference $that_commit)

I suspect that 2c6b6d9f (help: make option --help open man pages only for Git commands, 2016-08-26) is what you meant (the author CC'ed).

"new command" meaning the "git help" command?

Meaning "git commit --help -i" becomes "git help ... commit -i", and because the command line parser of "git help" accepts dashed options after "commit", it works just like "git help ... -i commit" does?

It is a request to read the help information for "git commit" using the "--info" backend, right? Similarly, "git commit --help -m" would do the manpage and "git commit --help -w" would show the manpage in the browser?

It sounds like a sensible behaviour to me (even though relying on the behaviour of "git help" that takes dashed options after "commit" makes me feel somewhat dirty). So ...

... I am not sure what you are fixing. Puzzled...