diff -Nru a/hcache.c b/hcache.c
--- a/hcache.c	2004-09-02 14:27:26 +02:00
+++ b/hcache.c	2004-09-18 13:03:39 +02:00
@@ -37,6 +37,7 @@
 #include "mime.h"
 #include "mx.h"
 #include "lib.h"
+#include "md5.h"
 
 #if HAVE_GDBM
 static struct
@@ -412,7 +413,7 @@
 	SPAM_LIST *sp = SpamList;
 	RX_LIST   *rx = NoSpamList;
 
-	crc = crc32(crc, (unsigned char const *) "sithglan@stud.uni-erlangen.de|hcache.c|20040902122726|65256", mutt_strlen("sithglan@stud.uni-erlangen.de|hcache.c|20040902122726|65256"));
+	crc = crc32(crc, (unsigned char const *) "sithglan@stud.uni-erlangen.de|hcache.c|20040918110339|18700", mutt_strlen("sithglan@stud.uni-erlangen.de|hcache.c|20040918110339|18700"));
 
 #if HAVE_LANGINFO_CODESET
 	crc = crc32(crc, (unsigned char const *) Charset, mutt_strlen(Charset));
@@ -487,6 +488,45 @@
 	return d;
 }
 
+/* Append md5sumed folder to path if path is a directory. */
+
+static const char *
+mutt_hcache_per_folder(const char *path, const char *folder)
+{
+	static char mutt_hcache_per_folder_path[_POSIX_PATH_MAX];
+	struct stat path_stat;
+	MD5_CTX md5;
+	unsigned char md5sum[16];
+	int ret;
+
+	ret = stat(path, &path_stat);
+	if (ret < 0) {
+		return path;
+	}
+
+	if (! S_ISDIR(path_stat.st_mode)) {
+		return path;
+	}
+
+	MD5Init(&md5);
+	MD5Update(&md5, (unsigned char *) folder, strlen(folder));
+	MD5Final(md5sum, &md5);
+
+	ret = snprintf(mutt_hcache_per_folder_path, _POSIX_PATH_MAX,
+                        "%s/%02x%02x%02x%02x%02x%02x%02x%02x"
+                        "%02x%02x%02x%02x%02x%02x%02x%02x",
+			path, md5sum[0], md5sum[1], md5sum[2], md5sum[3],
+			md5sum[4], md5sum[5], md5sum[6], md5sum[7], md5sum[8],
+			md5sum[9], md5sum[10], md5sum[11], md5sum[12],
+			md5sum[13], md5sum[14], md5sum[15]);
+
+	if (ret <= 0) {
+		return path;
+	}
+
+	return mutt_hcache_per_folder_path;
+}
+
 HEADER *
 mutt_hcache_restore(const unsigned char *d, HEADER **oh)
 {
@@ -537,6 +577,8 @@
 		return NULL;
 	}
 
+	path = mutt_hcache_per_folder(path, folder);
+
 	h->db = gdbm_open((char *) path, pagesize, GDBM_WRCREAT, 00600, NULL);
 	if (h->db) {
 		return h;
@@ -678,6 +720,8 @@
 		FREE(& h);
 		return NULL;
 	}
+
+	path = mutt_hcache_per_folder(path, folder);
 
 	snprintf (h->lockfile, _POSIX_PATH_MAX, "%s-lock-hack", path);
 
diff -Nru a/init.h b/init.h
--- a/init.h	2004-08-26 22:31:23 +02:00
+++ b/init.h	2004-09-18 17:57:51 +02:00
@@ -1027,8 +1027,11 @@
   { "header_cache", DT_PATH, R_NONE, UL &HeaderCache, 0 },
   /*
   ** .pp
-  ** Path to the header cache file. If unset no cache will be used. Otherwise
-  ** the cache will be enabled for Maildir and IMAP mailboxes.
+  ** The header_cache variable points to the header cache database. If
+  ** header_cache points to a directory there will be created one header cache
+  ** database per folder within this directory. If it doesn't point to a directory a
+  ** global header cache for all folders is used. Per default it is unset and so
+  ** no header caching will be used.
   */
   { "maildir_header_cache_verify", DT_BOOL, R_NONE, OPTHCACHEVERIFY, 1 },
   /*