From 0ef88cc19d427b644e22e591ad60a874ca21bc7b Mon Sep 17 00:00:00 2001
From: "Matt A. Tobin" <email@mattatobin.com>
Date: Sun, 10 Nov 2019 20:22:34 -0500
Subject: [PATCH] Bug 1444389 - Fix crash in
 nsImapProtocol::HandleMessageDownLoadLine().

Tag #1273
---
 mailnews/imap/src/nsImapProtocol.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mailnews/imap/src/nsImapProtocol.cpp b/mailnews/imap/src/nsImapProtocol.cpp
index 9114a28f2f..5e2639a5a4 100644
--- a/mailnews/imap/src/nsImapProtocol.cpp
+++ b/mailnews/imap/src/nsImapProtocol.cpp
@@ -3806,6 +3806,7 @@ nsImapProtocol::PostLineDownLoadEvent(const char *line, uint32_t uidOfMessage)
 void nsImapProtocol::HandleMessageDownLoadLine(const char *line, bool isPartialLine,
                                                char *lineCopy)
 {
+  NS_ENSURE_TRUE_VOID(line);
   NS_PRECONDITION(lineCopy == nullptr || !PL_strcmp(line, lineCopy),
                   "line and lineCopy must contain the same string");
   const char *messageLine = line;