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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
var.c 
/*
 * GIT - The information manager from hell
 *
 * Copyright (C) Eric Biederman, 2005
 */
#include "cache.h"

static const char var_usage[] = "git-var [-l | <variable>]";

struct git_var {
	const char *name;
	const char *(*read)(int);
};
static struct git_var git_vars[] = {
	{ "GIT_COMMITTER_IDENT", git_committer_info },
	{ "GIT_AUTHOR_IDENT",   git_author_info },
	{ "", NULL },
};

static void list_vars(void)
{
	struct git_var *ptr;
	for(ptr = git_vars; ptr->read; ptr++) {
		printf("%s=%s\n", ptr->name, ptr->read(0));
	}
}

static const char *read_var(const char *var)
{
	struct git_var *ptr;
	const char *val;
	val = NULL;
	for(ptr = git_vars; ptr->read; ptr++) {
		if (strcmp(var, ptr->name) == 0) {
			val = ptr->read(1);
			break;
		}
	}
	return val;
}

static int show_config(const char *var, const char *value)
{
	if (value)
		printf("%s=%s\n", var, value);
	else
		printf("%s\n", var);
	return git_default_config(var, value);
}

int main(int argc, char **argv)
{
	const char *val;
	if (argc != 2) {
		usage(var_usage);
	}

	setup_git_directory();
	val = NULL;

	if (strcmp(argv[1], "-l") == 0) {
		git_config(show_config);
		list_vars();
		return 0;
	}
	git_config(git_default_config);
	val = read_var(argv[1]);
	if (!val)
		usage(var_usage);

	printf("%s\n", val);

	return 0;
}
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