Re: [PATCH] credential.c: fix credential reading with regards to CR/LF

From: Junio C Hamano <gitster@pobox.com>
Date: Feb 14, 2020, 17:55 UTC
Message-ID: <xmqqmu9lnjdh.fsf@gitster-ct.c.googlers.com>
In-Reply-To: <pull.710.git.git.1581688196706.gitgitgadget@gmail.com>

"Johannes Schindelin via GitGitGadget" <gitgitgadget@gmail.com> writes:

Show 17 quoted lines

> From: Nikita Leonov <nykyta.leonov@gmail.com>
>
> This fix makes using Git credentials more friendly to Windows users. In
> previous version it was unable to finish input correctly without
> configuration changes (tested in PowerShell, CMD, Cygwin).
>
> We know credential filling should be finished by empty input, but the
> current implementation does not take into account CR/LF ending, and
> hence instead of the empty string we get '\r', which is interpreted as
> an incorrect string.
>
> So this commit changes default reading function to a more Windows
> compatible reading function.
>
> Signed-off-by: Nikita Leonov <nykyta.leonov@gmail.com>
> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
> ---

In the older days, strbuf_getline() used to be what we have as strbuf_getdelim() today, i.e. explicitly request what record separator to use to grab a line.

The use of strbuf_getline_lf() we see in the pre-image of this patch came from 8f309aeb ("strbuf: introduce strbuf_getline_{lf,nul}()", 2016-01-13), which mechanically replaced the use of strbuf_getline(... '\n'), in anticipation for later effort to identify ones that are better to accept CRLF and turn them into _crlf variant. Later all the callers of (old) strbuf_getline() went away, and strbuf_getline_crlf() that allowed both LF and CRLF termination (which is most friendly to human-readable line of text) took over the shortest and sweetest name, strbuf_getline().

So, the "later" effort just happend to this code. It was a bit overdue, but it's better late than never.

Show 15 quoted lines

>  credential.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/credential.c b/credential.c
> index 62be651b03..65989dfa4d 100644
> --- a/credential.c
> +++ b/credential.c
> @@ -146,7 +146,7 @@ int credential_read(struct credential *c, FILE *fp)
>  {
>  	struct strbuf line = STRBUF_INIT;
>  
> -	while (strbuf_getline_lf(&line, fp) != EOF) {
> +	while (strbuf_getline(&line, fp) != EOF) {
>  		char *key = line.buf;
>  		char *value = strchr(key, '=');

There are many more conversions of strbuf_getline(..., '\n') to strbuf_getline_lf(...) made by 8f309aeb to other parts of credential stuff. Has anybody from the Windows side made sure these other ones are also better to accept CRLF, too?

I'd wait for a bit to hear either "oh, we found two more and here is an updated patch" or "we looked at them and this is the only one", before touching this patch.

Thanks.