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Revision aba91192ae39cd1a2f79e7ed91e966df3cfe10b7 authored by Carlos Rica on 09 September 2007, 00:39:29 UTC, committed by Junio C Hamano on 10 September 2007, 04:30:54 UTC 
git-tag -s must fail if gpg cannot sign the tag.
 
Most of this patch code and message was written by Shawn O. Pearce.
I made some tests to know what the problem was, and then I changed
the code related with the SIGPIPE signal.

If the user has misconfigured `user.signingkey` in their .git/config
or just doesn't have any secret keys on their keyring and they ask
for a signed tag with `git tag -s` we better make sure the resulting
tag was actually signed by gpg.

Prior versions of builtin git-tag allowed this failure to slip
by without error as they were not checking the return value of
the finish_command() so they did not notice when gpg exited with
an error exit status.  They also did not fail if gpg produced an
empty output or if read_in_full received an error from the read
system call while trying to read the pipe back from gpg.

Finally, we did not actually honor any return value from the do_sign
function as it returns ssize_t but was being stored into an unsigned
long.  This caused the compiler to optimize out the die condition,
allowing git-tag to continue along and create the tag object.

However, when gpg gets a wrong username, it exits before any read was done
and then the writing process receives SIGPIPE and program is terminated.
By ignoring this signal, anyway, the function write_or_die gets EPIPE from
write_in_full and exits returning 0 to the system without a message.
Here we better call to write_in_full directly so we can fail
printing a message and return safely to the caller.

With these issues fixed `git-tag -s` will now fail to create the
tag and will report a non-zero exit status to its caller, thereby
allowing automated helper scripts to detect (and recover from)
failure if gpg is not working properly.

Proposed-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Carlos Rica <jasampler@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 7b02b85
Raw File
builtin-symbolic-ref.c 
#include "builtin.h"
#include "cache.h"
#include "refs.h"

static const char git_symbolic_ref_usage[] =
"git-symbolic-ref [-q] [-m <reason>] name [ref]";

static void check_symref(const char *HEAD, int quiet)
{
	unsigned char sha1[20];
	int flag;
	const char *refs_heads_master = resolve_ref(HEAD, sha1, 0, &flag);

	if (!refs_heads_master)
		die("No such ref: %s", HEAD);
	else if (!(flag & REF_ISSYMREF)) {
		if (!quiet)
			die("ref %s is not a symbolic ref", HEAD);
		else
			exit(1);
	}
	puts(refs_heads_master);
}

int cmd_symbolic_ref(int argc, const char **argv, const char *prefix)
{
	int quiet = 0;
	const char *msg = NULL;

	git_config(git_default_config);

	while (1 < argc) {
		const char *arg = argv[1];
		if (arg[0] != '-')
			break;
		else if (!strcmp("-q", arg))
			quiet = 1;
		else if (!strcmp("-m", arg)) {
			argc--;
			argv++;
			if (argc <= 1)
				break;
			msg = argv[1];
			if (!*msg)
				die("Refusing to perform update with empty message");
		}
		else if (!strcmp("--", arg)) {
			argc--;
			argv++;
			break;
		}
		else
			die("unknown option %s", arg);
		argc--;
		argv++;
	}

	switch (argc) {
	case 2:
		check_symref(argv[1], quiet);
		break;
	case 3:
		create_symref(argv[1], argv[2], msg);
		break;
	default:
		usage(git_symbolic_ref_usage);
	}
	return 0;
}
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