From: Kevin McCarthy <kevin@8t8.us>
Date: Sun, 12 Aug 2018 00:59:54 +0000 (-0700)
Subject: Always check UID vs MSN when handling FETCH
X-Git-Tag: 2019-10-25~671^2~10
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=43f35bd363ab2c61ba589251169caccecf5f58ad;p=neomutt

Always check UID vs MSN when handling FETCH

Ensure the UID vs MSN check is always done before flags are processed,
not just if the UID happened to appear before the FLAGS.

Improve the debug messages to make it clearer why a fetch response is
being skipped.
---

diff --git a/imap/command.c b/imap/command.c
index b91379e0d..6be9c0834 100644
--- a/imap/command.c
+++ b/imap/command.c
@@ -285,20 +285,28 @@ static void cmd_parse_fetch(struct ImapData *idata, char *s)
 {
   unsigned int msn, uid;
   struct Header *h = NULL;
+  char *flags = NULL;
+  int uid_checked = 0;
   int server_changes = 0;
 
   mutt_debug(3, "Handling FETCH\n");
 
-  if (mutt_str_atoui(s, &msn) < 0 || msn < 1 || msn > idata->max_msn)
+  if (mutt_str_atoui(s, &msn) < 0)
   {
-    mutt_debug(3, "#1 FETCH response ignored for this message\n");
+    mutt_debug(3, "Skipping FETCH response - illegal MSN\n");
+    return;
+  }
+
+  if ((msn < 1) || (msn > idata->max_msn))
+  {
+    mutt_debug(3, "Skipping FETCH response - MSN %u out of range\n", msn);
     return;
   }
 
   h = idata->msn_index[msn - 1];
   if (!h || !h->active)
   {
-    mutt_debug(3, "#2 FETCH response ignored for this message\n");
+    mutt_debug(3, "Skipping FETCH response - MSN %u not in msn_index\n", msn);
     return;
   }
 
@@ -320,16 +328,27 @@ static void cmd_parse_fetch(struct ImapData *idata, char *s)
 
     if (mutt_str_strncasecmp("FLAGS", s, 5) == 0)
     {
-      imap_set_flags(idata, h, s, &server_changes);
-      if (server_changes)
+      flags = s;
+      if (uid_checked)
+        break;
+
+      s += 5;
+      SKIPWS(s);
+      if (*s != '(')
       {
-        /* If server flags could conflict with neomutt's flags, reopen the mailbox. */
-        if (h->changed)
-          idata->reopen |= IMAP_EXPUNGE_PENDING;
-        else
-          idata->check_status = IMAP_FLAGS_PENDING;
+        mutt_debug(1, "bogus FLAGS response: %s\n", s);
+        return;
+      }
+      s++;
+      while (*s && *s != ')')
+        s++;
+      if (*s == ')')
+        s++;
+      else
+      {
+        mutt_debug(1, "Unterminated FLAGS response: %s\n", s);
+        return;
       }
-      return;
     }
     else if (mutt_str_strncasecmp("UID", s, 3) == 0)
     {
@@ -337,22 +356,38 @@ static void cmd_parse_fetch(struct ImapData *idata, char *s)
       SKIPWS(s);
       if (mutt_str_atoui(s, &uid) < 0)
       {
-        mutt_debug(2, "Illegal UID.  Skipping update.\n");
+        mutt_debug(1, "Illegal UID.  Skipping update.\n");
         return;
       }
       if (uid != HEADER_DATA(h)->uid)
       {
-        mutt_debug(2, "FETCH UID vs MSN mismatch.  Skipping update.\n");
+        mutt_debug(1, "UID vs MSN mismatch.  Skipping update.\n");
         return;
       }
+      uid_checked = 1;
+      if (flags)
+        break;
       s = imap_next_word(s);
     }
     else if (*s == ')')
-      s++; /* end of request */
+      break; /* end of request */
     else if (*s)
     {
       mutt_debug(2, "Only handle FLAGS updates\n");
-      return;
+      break;
+    }
+  }
+
+  if (flags)
+  {
+    imap_set_flags(idata, h, flags, &server_changes);
+    if (server_changes)
+    {
+      /* If server flags could conflict with mutt's flags, reopen the mailbox. */
+      if (h->changed)
+        idata->reopen |= IMAP_EXPUNGE_PENDING;
+      else
+        idata->check_status = IMAP_FLAGS_PENDING;
     }
   }
 }