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Revision 03818a4a94cbe8154eae433892e92d58d215dade authored by Jeff King on 14 October 2013, 22:45:00 UTC, committed by Junio C Hamano on 15 October 2013, 17:41:49 UTC 
split_ident: parse timestamp from end of line
 
Split_ident currently parses left to right. Given this
input:

  Your Name <email@example.com> 123456789 -0500\n

We assume the name starts the line and runs until the first
"<".  That starts the email address, which runs until the
first ">".  Everything after that is assumed to be the
timestamp.

This works fine in the normal case, but is easily broken by
corrupted ident lines that contain an extra ">". Some
examples seen in the wild are:

  1. Name <email>-<> 123456789 -0500\n

  2. Name <email> <Name<email>> 123456789 -0500\n

  3. Name1 <email1>, Name2 <email2> 123456789 -0500\n

Currently each of these produces some email address (which
is not necessarily the one the user intended) and end up
with a NULL date (which is generally interpreted as the
epoch by "git log" and friends).

But in each case we could get the correct timestamp simply
by parsing from the right-hand side, looking backwards for
the final ">", and then reading the timestamp from there.

In general, it's a losing battle to try to automatically
guess what the user meant with their broken crud. But this
particular workaround is probably worth doing.  One, it's
dirt simple, and can't impact non-broken cases. Two, it
doesn't catch a single breakage we've seen, but rather a
large class of errors (i.e., any breakage inside the email
angle brackets may affect the email, but won't spill over
into the timestamp parsing). And three, the timestamp is
arguably more valuable to get right, because it can affect
correctness (e.g., in --until cutoffs).

This patch implements the right-to-left scheme described
above. We adjust the tests in t4212, which generate a commit
with such a broken ident, and now gets the timestamp right.
We also add a test that fsck continues to detect the
breakage.

For reference, here are pointers to the breakages seen (as
numbered above):

[1] http://article.gmane.org/gmane.comp.version-control.git/221441

[2] http://article.gmane.org/gmane.comp.version-control.git/222362

[3] http://perl5.git.perl.org/perl.git/commit/13b79730adea97e660de84bbe67f9d7cbe344302

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 02a110a
Raw File
copy.c 
#include "cache.h"

int copy_fd(int ifd, int ofd)
{
	while (1) {
		char buffer[8192];
		char *buf = buffer;
		ssize_t len = xread(ifd, buffer, sizeof(buffer));
		if (!len)
			break;
		if (len < 0) {
			int read_error = errno;
			close(ifd);
			return error("copy-fd: read returned %s",
				     strerror(read_error));
		}
		while (len) {
			int written = xwrite(ofd, buf, len);
			if (written > 0) {
				buf += written;
				len -= written;
			}
			else if (!written) {
				close(ifd);
				return error("copy-fd: write returned 0");
			} else {
				int write_error = errno;
				close(ifd);
				return error("copy-fd: write returned %s",
					     strerror(write_error));
			}
		}
	}
	close(ifd);
	return 0;
}

static int copy_times(const char *dst, const char *src)
{
	struct stat st;
	struct utimbuf times;
	if (stat(src, &st) < 0)
		return -1;
	times.actime = st.st_atime;
	times.modtime = st.st_mtime;
	if (utime(dst, &times) < 0)
		return -1;
	return 0;
}

int copy_file(const char *dst, const char *src, int mode)
{
	int fdi, fdo, status;

	mode = (mode & 0111) ? 0777 : 0666;
	if ((fdi = open(src, O_RDONLY)) < 0)
		return fdi;
	if ((fdo = open(dst, O_WRONLY | O_CREAT | O_EXCL, mode)) < 0) {
		close(fdi);
		return fdo;
	}
	status = copy_fd(fdi, fdo);
	if (close(fdo) != 0)
		return error("%s: close error: %s", dst, strerror(errno));

	if (!status && adjust_shared_perm(dst))
		return -1;

	return status;
}

int copy_file_with_time(const char *dst, const char *src, int mode)
{
	int status = copy_file(dst, src, mode);
	if (!status)
		return copy_times(dst, src);
	return status;
}
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