[PATCH setxkbmap] Eliminate limitations on path length.

[Mark Kettenis]

> From: Van de Bugger <van.de.bugger at gmail.com>
> Date: Wed, 16 Feb 2011 00:15:52 +0300
> 
> >From 0aaae5b3c0d6183e2791c30155bae40132a0c779 Mon Sep 17 00:00:00 2001
> From: Van de Bugger <van.de.bugger at gmail.com>
> Date: Tue, 15 Feb 2011 23:55:28 +0300
> Subject: [PATCH setxkbmap] Eliminate limitations on path length.
> 
> ...by using dynamically allocated buffers. No need in PATH_MAX,
> MAXPATHLEN. No more "Path too long" errors.

Not really.  Instead fopen(3) will fail and a more cryptic "Didn't
find" error message will be printed.  There really is very little
benefit in dynamicaly allocating paths.  All OSes have a fixed maximum
path length, even the Hurd (contrary to what people claim).

Also, please, please don't write "char * buffer"; spaces at both sides
of the '*' suggests it is the binary multiplication operator.  The
proper style is for pointers is "char *buffer".

> ---
>  setxkbmap.c |   72 ++++++++++++++++++++++++++++++++++++----------------------
>  1 files changed, 45 insertions(+), 27 deletions(-)
> 
> diff --git a/setxkbmap.c b/setxkbmap.c
> index 3d3b7d8..6777b1b 100644
> --- a/setxkbmap.c
> +++ b/setxkbmap.c
> @@ -24,6 +24,7 @@
>  
>   ********************************************************/
>  
> +#include <stdarg.h>
>  #include <stdio.h>
>  #include <stdlib.h>
>  #include <locale.h>
> @@ -36,14 +37,6 @@
>  #include <X11/extensions/XKBconfig.h>
>  #include <X11/extensions/XKBrules.h>
>  
> -#ifndef PATH_MAX
> -#ifdef MAXPATHLEN
> -#define PATH_MAX MAXPATHLEN
> -#else
> -#define PATH_MAX 1024
> -#endif
> -#endif
> -
>  #ifndef DFLT_XKB_CONFIG_ROOT
>  #define DFLT_XKB_CONFIG_ROOT "/usr/share/X11/xkb"
>  #endif
> @@ -170,6 +163,7 @@ static int deviceSpec = XkbUseCoreKbd;
>  
>  /***====================================================================***/
>  
> +char * rprintf( char const * format, ... );
>  Bool addToList(list_t * list, char *newVal);
>  void usage(int argc, char **argv);
>  void dumpNames(Bool wantRules, Bool wantCNames);
> @@ -189,6 +183,42 @@ void printKeymap(void);
>  /***====================================================================***/
>  
>  /*
> +    Like sprintf, but returns freshly allocated string instead writing it to
> +    pre-allocated buffer. Do not forget to free returned strung.
> +*/
> +
> +char *
> +rprintf(char const * format, ...)
> +{
> +    va_list args;
> +    char * buffer = NULL;
> +    int allocated = 0;
> +    int required  = 100;
> +    do 
> +    {
> +        buffer = realloc(buffer, required + 1);
> +        if (buffer == NULL)
> +        {
> +            ERR("Out of memory.\n");
> +            abort();
> +        }
> +        allocated = required + 1;
> +        va_start(args, format);
> +        required = vsnprintf(buffer, allocated, format, args);
> +        va_end(args);
> +        if (required < 0)
> +        {
> +            ERR1("`vsnprintf' returned unexpected error (%d).\n", required);
> +            abort();
> +        }
> +    }
> +    while (required >= allocated);
> +    return buffer;
> +}
> +
> +/***====================================================================***/
> +
> +/*
>      If newVal is NULL or empty string, the list is cleared.
>      Otherwise newVal is added to the end of the list (if it is not present in the list yet).
>  */
> @@ -623,7 +653,6 @@ FILE *
>  findFileInPath(char *name, char *subdir)
>  {
>      register int i;
> -    char buf[PATH_MAX];
>      FILE *fp;
>  
>      if (name[0] == '/')
> @@ -635,16 +664,11 @@ findFileInPath(char *name, char *subdir)
>      }
>      for (i = 0; (i < inclPath.num); i++)
>      {
> -        if (snprintf(buf, PATH_MAX, "%s/%s%s", inclPath.item[i], subdir, name) >=
> -            PATH_MAX)
> -        {
> -            VMSG3(0, "Path too long (%s/%s%s). Ignored.\n", inclPath.item[i],
> -                  subdir, name);
> -            continue;
> -        }
> -        fp = fopen(buf, "r");
> +        char * path = rprintf("%s/%s%s", inclPath.item[i], subdir, name);
> +        fp = fopen(path, "r");
>          if ((verbose > 7) || ((!fp) && (verbose > 5)))
> -            MSG2("%s file %s\n", (fp ? "Found" : "Didn't find"), buf);
> +            MSG2("%s file %s\n", (fp ? "Found" : "Didn't find"), path);
> +        free(path);
>          if (fp != NULL)
>              return fp;
>      }
> @@ -824,7 +848,6 @@ applyRules(void)
>      if (settings.model.src || settings.layout.src || settings.variant.src
>          || options.item)
>      {
> -        char buf[PATH_MAX];
>          XkbComponentNamesRec rnames;
>  
>          if (settings.variant.src < settings.layout.src)
> @@ -852,14 +875,9 @@ applyRules(void)
>               * we succeed with */
>              for (i = 0; (i < inclPath.num) && (!rules); i++)
>              {
> -                if (snprintf(buf, PATH_MAX, "%s/rules/%s",
> -                             inclPath.item[i], rfName) >= PATH_MAX)
> -                {
> -                    VMSG2(0, "Path too long (%s/rules/%s). Ignored.\n",
> -                          inclPath.item[i], rfName);
> -                    continue;
> -                }
> -                rules = XkbRF_Load(buf, settings.locale.value, True, True);
> +                char * path = rprintf("%s/rules/%s", inclPath.item[i], rfName);
> +                rules = XkbRF_Load(path, settings.locale.value, True, True);
> +                free(path);
>              }
>          }
>          if (!rules)
> -- 
> 1.7.4
> 
> 
> 
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