when building message cache dirs, mkdir new and tmp

makes cache dirs get recognized as Maildirs to enable reading them
as offline backups

bcache.c

@@ -25,6 +25,7 @@
#include <errno.h>
#include <dirent.h>
#include <stdio.h>
#include <libgen.h>

#include "mutt.h"
#include "account.h"
@@ -65,7 +66,7 @@ static int bcache_path(ACCOUNT *account, const char *mailbox,

  mutt_encode_path (path, sizeof (path), NONULL (mailbox));

  len = snprintf (dst, dstlen-1, "%s/%s%s%s", MessageCachedir,
  len = snprintf (dst, dstlen-1, "%s/%s%s%scur/", MessageCachedir,
		  host, path,
		  (*path && path[mutt_strlen (path) - 1] == '/') ? "" : "/");

@@ -129,6 +130,7 @@ FILE* mutt_bcache_get(body_cache_t *bcache, const char *id)
FILE* mutt_bcache_put(body_cache_t *bcache, const char *id, int tmp)
{
  char path[_POSIX_PATH_MAX];
  char newpath[_POSIX_PATH_MAX];
  FILE* fp;
  char* s;
  struct stat sb;
@@ -157,6 +159,20 @@ FILE* mutt_bcache_put(body_cache_t *bcache, const char *id, int tmp)
    s = strchr (s + 1, '/');
  }

  /* make sure new and tmp dirs exist in parent to be like real maildirs */
  if (s = dirname(path)) {
    s = dirname(s);

    snprintf (newpath, sizeof (newpath), "%s/new", s);
    if (stat (newpath, &sb) < 0 && (errno != ENOENT || mkdir (newpath, 0777) < 0))
      return NULL;

    snprintf (newpath, sizeof (newpath), "%s/tmp", s);
    if (stat (newpath, &sb) < 0 && (errno != ENOENT || mkdir (newpath, 0777) < 0))
      return NULL;
  } else
    return NULL;

  out:
  dprint (3, (debugfile, "bcache: put: '%s'\n", path));