Recommendations for updating error() to error_errno()

Hi, Our team works on enhance logging practices by learning from historical log revisions in evolution. And we find three patches that update error(..., strerror(errmp)) to error_errno(...).

While applying this rule to git-2.14.2, we find 9 missed spot in file refs/files-backend.c, 1 in apply.c, 2 in trace.c, 4 in dir-iterator.c:.

Here are the missed spots:
1) Line 1734 in file git-2.14.2/refs/files-backend.c:
ret = raceproof_create_file(path.buf, rename_tmp_log_callback, &cb);
if (ret) {
	if (errno == EISDIR)
		error("directory not empty: %s", path.buf);
	else
		error("unable to move logfile %s to %s: %s",
			tmp.buf, path.buf,
			strerror(cb.true_errno));
}

2) Line 1795 in file git-2.14.2/refs/files-backend.c: 
if (log && rename(sb_oldref.buf, tmp_renamed_log.buf)) {
	ret = error("unable to move logfile logs/%s to logs/"TMP_RENAMED_LOG": %s",
			oldrefname, strerror(errno));
	goto out;
}

3) Line 1880, 1884 in file git-2.14.2/refs/files-backend.c:
rollbacklog:
	if (logmoved && rename(sb_newref.buf, sb_oldref.buf))
		error("unable to restore logfile %s from %s: %s",
			oldrefname, newrefname, strerror(errno));
	if (!logmoved && log &&
	    rename(tmp_renamed_log.buf, sb_oldref.buf))
		error("unable to restore logfile %s from logs/"TMP_RENAMED_LOG": %s",
			oldrefname, strerror(errno));
4) Line 2247 in file git-2.14.2/refs/files-backend.c:
if (commit_ref(lock) < 0)
	return error("unable to write symref for %s: %s", refname,
		     strerror(errno));

5) Line 2366 in file git-2.14.2/refs/files-backend.c:
if (fseek(logfp, 0, SEEK_END) < 0)
	ret = error("cannot seek back reflog for %s: %s",
		    refname, strerror(errno));

6) Line 2378, 2384 in file git-2.14.2/refs/files-backend.c:
if (fseek(logfp, pos - cnt, SEEK_SET)) {
	ret = error("cannot seek back reflog for %s: %s",
	    refname, strerror(errno));
        break;
} 
nread = fread(buf, cnt, 1, logfp);
if (nread != 1) {
	ret = error("cannot read %d bytes from reflog for %s: %s",
	    cnt, refname, strerror(errno));
	break;
}

7) Line 3312 in file git-2.14.2/refs/files-backend.c:
cb.newlog = fdopen_lock_file(&reflog_lock, "w");
if (!cb.newlog) {
	error("cannot fdopen %s (%s)",
	      get_lock_file_path(&reflog_lock), strerror(errno));
	goto failure;
}

8) Line 3337 in file git-2.14.2/refs/files-backend.c:
if (close_lock_file(&reflog_lock)) {
        status |= error("couldn't write %s: %s", log_file,
	   strerror(errno));

9) Line 3348 in file git-2.14.2/refs/files-backend.c:
static int files_reflog_expire(struct ref_store *ref_store,...
{
	...
		} else if (commit_lock_file(&reflog_lock)) {
			status |= error("unable to write reflog '%s' (%s)",
					log_file, strerror(errno));

10) Line 4859 in file git-2.14.2/apply.c:
fd = open(arg, O_RDONLY);
if (fd < 0) {
	error(_("can't open patch '%s': %s"), arg, strerror(errno));
	res = -128;
	free(to_free);
	goto end;
}

11) Line 64 in file git-2.14.2/trace.c:
int fd = open(trace, O_WRONLY | O_APPEND | O_CREAT, 0666);
if (fd == -1) {
	warning("could not open '%s' for tracing: %s",
		trace, strerror(errno));

12) Line 133 in file git-2.14.2/trace.c:
static void trace_write(struct trace_key *key, const void *buf, unsigned len)
{
	if (write_in_full(get_trace_fd(key), buf, len) < 0) {
		normalize_trace_key(&key);
		warning("unable to write trace for %s: %s",
			key->key, strerror(errno));

13) Line 74 in file git-2.14.2/dir-iterator.c:
level->dir = opendir(iter->base.path.buf);
if (!level->dir && errno != ENOENT) {
	warning("error opening directory %s: %s",
		iter->base.path.buf, strerror(errno));
        /* Popping the level is handled below */
}

14) Line 125, 128 in file git-2.14.2/dir-iterator.c:
de = readdir(level->dir);
if (!de) {
	/* This level is exhausted; pop up a level. */
	if (errno) {
		warning("error reading directory %s: %s",
			iter->base.path.buf, strerror(errno));
	} else if (closedir(level->dir))
		warning("error closing directory %s: %s",
			iter->base.path.buf, strerror(errno));

15) Line 143 in file git-2.14.2/dir-iterator.c:
if (lstat(iter->base.path.buf, &iter->base.st) < 0) {
	if (errno != ENOENT)
		warning("error reading path '%s': %s",
			iter->base.path.buf,
			strerror(errno));

16) Line 174 in file git-2.14.2/dir-iterator.c:
if (level->dir && closedir(level->dir)) {
	strbuf_setlen(&iter->base.path, level->prefix_len);
	warning("error closing directory %s: %s",
           iter->base.path.buf, strerror(errno));

Following are the 5 patches that support our opinion:
1) Line 2182 in file git/versions/git-2.8.6/config.c:
 	if (commit_lock_file(lock) < 0) {
-		error("could not write config file %s: %s", config_filename,
-		      strerror(errno));
+		error_errno("could not write config file %s", config_filename);
 		ret = CONFIG_NO_WRITE;
 		lock = NULL;
 		goto out_free;
 	}

2) Line 2389 in file git/versions/git-2.8.6/config.c:
 unlock_and_out:
 	if (commit_lock_file(lock) < 0)
-		ret = error("could not write config file %s: %s",
-			    config_filename, strerror(errno));
+		ret = error_errno("could not write config file %s",
+				  config_filename);
 out:
 	free(filename_buf);

3) Line 1825 in file git/versions/git-2.8.6/fast-import.c:
 	dump_marks_helper(f, 0, marks);
 	if (commit_lock_file(&mark_lock)) {
-		failure |= error("Unable to write file %s: %s",
-			export_marks_file, strerror(errno));
+		failure |= error_errno("Unable to write file %s",
+				       export_marks_file);

4) Line 863 in file git-2.8.6/bisect.c: 
 	/* Create file BISECT_ANCESTORS_OK. */
 	fd = open(filename, O_CREAT | O_TRUNC | O_WRONLY, 0600);
 	if (fd < 0)
-		warning("could not create file '%s': %s",
-			filename, strerror(errno));
+		warning_errno("could not create file '%s'",
+			      filename);
 	else
 		close(fd);

5) Line 78 in file git-2.8.6/ident.c
 	mailname = fopen("/etc/mailname", "r");
 	if (!mailname) {
 		if (errno != ENOENT)
-			warning("cannot open /etc/mailname: %s",
-				strerror(errno));
+			warning_errno("cannot open /etc/mailname");
 		return -1;
 	}

Thanks for reading, we are looking forward to your reply about the correctness of our suggestion. May you a good day ^^

Best regards, Xu