Memcpy header cache fetch values to ensure alignment.

While testing the hcache buffer pool changes, I noticed a misaligned
pointer warning when using LMDB.

The other header cache backends must ensure alignment of the pointer
they return, but LMDB apparently does not.

Instead of directly assigning and dereferencing the pointer fetched,
use memcpy to the appropriate type, just as the header cache restore
operation does.

4 files changed, 49 insertions, 35 deletions

diff --git a/imap/imap.c b/imap/imap.c
index ccba3a38..33469f5f 100644
--- a/imap/imap.c
+++ b/imap/imap.c
@@ -1800,9 +1800,9 @@ IMAP_STATUS* imap_mboxcache_get (IMAP_DATA* idata, const char* mbox, int create)
   IMAP_STATUS scache;
 #ifdef USE_HCACHE
   header_cache_t *hc = NULL;
-  unsigned int *uidvalidity = NULL;
-  unsigned int *uidnext = NULL;
-  unsigned long long *modseq = NULL;
+  void *puidvalidity = NULL;
+  void *puidnext = NULL;
+  void *pmodseq = NULL;
 #endif
 
   for (cur = idata->mboxcache; cur; cur = cur->next)
@@ -1829,28 +1829,36 @@ IMAP_STATUS* imap_mboxcache_get (IMAP_DATA* idata, const char* mbox, int create)
   hc = imap_hcache_open (idata, mbox);
   if (hc)
   {
-    uidvalidity = mutt_hcache_fetch_raw (hc, "/UIDVALIDITY", imap_hcache_keylen);
-    uidnext = mutt_hcache_fetch_raw (hc, "/UIDNEXT", imap_hcache_keylen);
-    modseq = mutt_hcache_fetch_raw (hc, "/MODSEQ", imap_hcache_keylen);
-    if (uidvalidity)
+    puidvalidity = mutt_hcache_fetch_raw (hc, "/UIDVALIDITY", imap_hcache_keylen);
+    puidnext = mutt_hcache_fetch_raw (hc, "/UIDNEXT", imap_hcache_keylen);
+    pmodseq = mutt_hcache_fetch_raw (hc, "/MODSEQ", imap_hcache_keylen);
+    if (puidvalidity)
     {
       if (!status)
       {
-        mutt_hcache_free ((void **)&uidvalidity);
-        mutt_hcache_free ((void **)&uidnext);
-        mutt_hcache_free ((void **)&modseq);
+        mutt_hcache_free ((void **)&puidvalidity);
+        mutt_hcache_free ((void **)&puidnext);
+        mutt_hcache_free ((void **)&pmodseq);
         mutt_hcache_close (hc);
         return imap_mboxcache_get (idata, mbox, 1);
       }
-      status->uidvalidity = *uidvalidity;
-      status->uidnext = uidnext ? *uidnext: 0;
-      status->modseq = modseq ? *modseq: 0;
+      memcpy (&status->uidvalidity, puidvalidity, sizeof(unsigned int));
+
+      if (puidnext)
+        memcpy (&status->uidnext, puidnext, sizeof(unsigned int));
+      else
+        status->uidnext = 0;
+
+      if (pmodseq)
+        memcpy (&status->modseq, pmodseq, sizeof(unsigned long long));
+      else
+        status->modseq = 0;
       dprint (3, (debugfile, "mboxcache: hcache uidvalidity %u, uidnext %u, modseq %llu\n",
                   status->uidvalidity, status->uidnext, status->modseq));
     }
-    mutt_hcache_free ((void **)&uidvalidity);
-    mutt_hcache_free ((void **)&uidnext);
-    mutt_hcache_free ((void **)&modseq);
+    mutt_hcache_free ((void **)&puidvalidity);
+    mutt_hcache_free ((void **)&puidnext);
+    mutt_hcache_free ((void **)&pmodseq);
     mutt_hcache_close (hc);
   }
 #endif
diff --git a/imap/message.c b/imap/message.c
index f32f5db6..48dc0437 100644
--- a/imap/message.c
+++ b/imap/message.c
@@ -228,14 +228,15 @@ int imap_read_headers (IMAP_DATA* idata, unsigned int msn_begin, unsigned int ms
   int evalhc = 0;
 
 #if USE_HCACHE
-  unsigned int *uid_validity = NULL;
-  unsigned int *puidnext = NULL;
+  void *puid_validity = NULL;
+  unsigned int uid_validity = 0;
+  void *puidnext = NULL;
   unsigned int uidnext = 0;
   int has_condstore = 0;
   int has_qresync = 0;
   int eval_condstore = 0;
   int eval_qresync = 0;
-  unsigned long long *pmodseq = NULL;
+  void *pmodseq = NULL;
   unsigned long long hc_modseq = 0;
   char *uid_seqset = NULL;
 #endif /* USE_HCACHE */
@@ -257,11 +258,13 @@ int imap_read_headers (IMAP_DATA* idata, unsigned int msn_begin, unsigned int ms
 
   if (idata->hcache && initial_download)
   {
-    uid_validity = mutt_hcache_fetch_raw (idata->hcache, "/UIDVALIDITY", imap_hcache_keylen);
+    puid_validity = mutt_hcache_fetch_raw (idata->hcache, "/UIDVALIDITY", imap_hcache_keylen);
+    if (puid_validity)
+      memcpy (&uid_validity, puid_validity, sizeof(unsigned int));
     puidnext = mutt_hcache_fetch_raw (idata->hcache, "/UIDNEXT", imap_hcache_keylen);
     if (puidnext)
     {
-      uidnext = *puidnext;
+      memcpy (&uidnext, puidnext, sizeof(unsigned int));;
       mutt_hcache_free ((void **)&puidnext);
     }
 
@@ -278,13 +281,13 @@ int imap_read_headers (IMAP_DATA* idata, unsigned int msn_begin, unsigned int ms
         has_qresync = 1;
     }
 
-    if (uid_validity && uidnext && *uid_validity == idata->uid_validity)
+    if (puid_validity && uidnext && (uid_validity == idata->uid_validity))
     {
       evalhc = 1;
       pmodseq = mutt_hcache_fetch_raw (idata->hcache, "/MODSEQ", imap_hcache_keylen);
       if (pmodseq)
       {
-        hc_modseq = *pmodseq;
+        memcpy (&hc_modseq, pmodseq, sizeof(unsigned long long));;
         mutt_hcache_free ((void **)&pmodseq);
       }
       if (hc_modseq)
@@ -300,7 +303,7 @@ int imap_read_headers (IMAP_DATA* idata, unsigned int msn_begin, unsigned int ms
           eval_condstore = 1;
       }
     }
-    mutt_hcache_free ((void **)&uid_validity);
+    mutt_hcache_free ((void **)&puid_validity);
   }
   if (evalhc)
   {
diff --git a/imap/util.c b/imap/util.c
index 0812bac3..42f07cc2 100644
--- a/imap/util.c
+++ b/imap/util.c
@@ -179,22 +179,24 @@ void imap_hcache_close (IMAP_DATA* idata)
 HEADER* imap_hcache_get (IMAP_DATA* idata, unsigned int uid)
 {
   char key[16];
-  unsigned int* uv;
+  void *data;
+  unsigned int uv;
   HEADER* h = NULL;
 
   if (!idata->hcache)
     return NULL;
 
   sprintf (key, "/%u", uid);
-  uv = (unsigned int*)mutt_hcache_fetch (idata->hcache, key,
-                                         imap_hcache_keylen);
-  if (uv)
+  data = mutt_hcache_fetch (idata->hcache, key,
+                            imap_hcache_keylen);
+  if (data)
   {
-    if (*uv == idata->uid_validity)
-      h = mutt_hcache_restore ((unsigned char*)uv, NULL);
+    memcpy (&uv, data, sizeof(unsigned int));
+    if (uv == idata->uid_validity)
+      h = mutt_hcache_restore ((unsigned char *)data, NULL);
     else
-      dprint (3, (debugfile, "hcache uidvalidity mismatch: %u", *uv));
-    mutt_hcache_free ((void **)&uv);
+      dprint (3, (debugfile, "hcache uidvalidity mismatch: %u", uv));
+    mutt_hcache_free ((void **)&data);
   }
 
   return h;
diff --git a/mh.c b/mh.c
index 37cef860..ad3c8253 100644
--- a/mh.c
+++ b/mh.c
@@ -1145,7 +1145,7 @@ static void maildir_delayed_parsing (CONTEXT * ctx, struct maildir **md,
 #if USE_HCACHE
   header_cache_t *hc = NULL;
   void *data;
-  struct timeval *when = NULL;
+  struct timeval when;
   struct stat lastchanged;
   int ret;
 #endif
@@ -1207,9 +1207,10 @@ static void maildir_delayed_parsing (CONTEXT * ctx, struct maildir **md,
       data = mutt_hcache_fetch (hc, p->h->path, strlen);
     else
       data = mutt_hcache_fetch (hc, p->h->path + 3, &maildir_hcache_keylen);
-    when = (struct timeval *) data;
+    if (data)
+      memcpy (&when, data, sizeof(struct timeval));
 
-    if (data != NULL && !ret && lastchanged.st_mtime <= when->tv_sec)
+    if (data != NULL && !ret && lastchanged.st_mtime <= when.tv_sec)
     {
       p->h = mutt_hcache_restore ((unsigned char *)data, &p->h);
       if (ctx->magic == MUTT_MAILDIR)