fix fpm log prefix message with wrong stdout/stderr notation

[sadapon2008]

This pr fixes https://bugs.php.net/bug.php?id=78334
The following code outputs messages to either stdout or stderr.

<?php
file_put_contents('php://stdout', "msg 1 - ");
usleep(1);
file_put_contents('php://stderr', "msg 2 - ");
usleep(1);
file_put_contents('php://stderr', "msg 3");

Expected results:

LOG LINE: [25-Jul-2019 23:34:52] WARNING: [pool unconfined] child 87539 said into stdout: "msg 1 - "
LOG LINE: [25-Jul-2019 23:34:52] WARNING: [pool unconfined] child 87539 said into stderr: "msg 2 - msg 3"

Actual results:

LOG LINE: [25-Jul-2019 23:34:52] WARNING: [pool unconfined] child 87539 said into stdout: "msg 1 - msg 2 - msg 3"

This is caused by the reuse of log stream introduced by #3471

[cmb69]

@bukka, could you please review?

[bukka]

This would be better to handle inside zlog_stream_set_msg_prefix as it won't be necessary to do another allocation ("stdout" and "stderr" have the same length). However to make it generic there should be a check added. Basically something like:

zlog_bool zlog_stream_set_msg_prefix(struct zlog_stream *stream, const char *fmt, ...) /* {{{ */
{
	char buf[MAX_WRAPPING_PREFIX_LENGTH];
	size_t len;
	va_list args;

	if (!stream->decorate) {
		return ZLOG_TRUE;
	}

	va_start(args, fmt);
	len = vsnprintf(buf, MAX_WRAPPING_PREFIX_LENGTH - 1, fmt, args);
	va_end(args);

	if (stream->msg_prefix_len < len) {
		stream->msg_prefix = stream->msg_prefix_len ? realloc(stream->msg_prefix, len + 1) : malloc(len + 1);
		if (stream->msg_prefix == NULL) {
			return ZLOG_FALSE;
		}
	}
	memcpy(stream->msg_prefix, buf, len);
	stream->msg_prefix[len] = 0;
	stream->msg_prefix_len = len;

	return len;
}

[bukka]

This should be kept and then just added behind the stdout condition (line 152: https://github.com/php/php-src/pull/4476/files#diff-57f24d1c50be851c62c450ad57b13675R152 )

[bukka]

This should be deleted

[bukka]

It changes only if they are different. It should be also wrapped in inline function as other flags.

[sadapon2008]

@bukka Thank you for your review.
I refactored code.
Please review again.

[bukka]

@sadapon2008 Sorry for the late review. The code looks good now. If you could squash it and push force it, that would be great! I will test it hopefully next weekend and if all good, I will merge it! Thanks!

[sadapon2008]

@bukka Thank you for your reply.
I have squashed and pushed force.
Please check again.

[bukka]

Merged as ffcf57f