From: Brandon Casey <drafnel@gmail.com>
Date: Thu, 06 Oct 2011 17:27:29 GMT
Subject: Re: [PATCH] mingw: avoid using strbuf in syslog
Message-ID: <CA+sFfMediaCnzFH6uKfVc_Bb+W+AA1nO+OdvB8vWjjrsD1kh9w@mail.gmail.com>
In-Reply-To: <1317920244-6320-1-git-send-email-kusmabite@gmail.com>

On Thu, Oct 6, 2011 at 11:57 AM, Erik Faye-Lund <kusmabite@gmail.com> wrote:
> strbuf can call die, which again can call syslog from git-daemon.
>
> Endless recursion is no fun; fix it by hand-rolling the logic.
>
> Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com>
> ---
> Fixes the problem Brandon pointed out...

Actually, Johannes should get that credit.  He brought up the whole
recursion issue.

>  compat/win32/syslog.c |   26 ++++++++++++++------------
>  1 files changed, 14 insertions(+), 12 deletions(-)
>
> diff --git a/compat/win32/syslog.c b/compat/win32/syslog.c
> index 42b95a9..3b8e2b7 100644
> --- a/compat/win32/syslog.c
> +++ b/compat/win32/syslog.c
> @@ -1,5 +1,4 @@
>  #include "../../git-compat-util.h"
> -#include "../../strbuf.h"
>
>  static HANDLE ms_eventlog;
>
> @@ -16,13 +15,8 @@ void openlog(const char *ident, int logopt, int facility)
>
>  void syslog(int priority, const char *fmt, ...)
>  {
> -       struct strbuf sb = STRBUF_INIT;
> -       struct strbuf_expand_dict_entry dict[] = {
> -               {"1", "% 1"},
> -               {NULL, NULL}
> -       };
>        WORD logtype;
> -       char *str;
> +       char *str, *pos;
>        int str_len;
>        va_list ap;
>
> @@ -39,11 +33,20 @@ void syslog(int priority, const char *fmt, ...)
>        }
>
>        str = malloc(str_len + 1);
> +       if (!str)
> +               return; /* no chance to report error */
> +

Just above this, warning() is used to at least print a message to
stderr if vsnprintf() fails.  It could be used here, and below when
realloc fails.

>        va_start(ap, fmt);
>        vsnprintf(str, str_len + 1, fmt, ap);
>        va_end(ap);
> -       strbuf_expand(&sb, str, strbuf_expand_dict_cb, &dict);
> -       free(str);
> +
> +       while ((pos = strstr(str, "%1")) != NULL) {
> +               str = realloc(str, ++str_len + 1);
> +               if (!str)
> +                       return;
> +               memmove(pos + 2, pos + 1, strlen(pos));
> +               pos[1] = ' ';
> +       }
>
>        switch (priority) {
>        case LOG_EMERG:

-Brandon