From c06ddd664f4a0f6e485f6f9f6b5086aa4719a441 Mon Sep 17 00:00:00 2001
From: Jeremy Harris <jgh146exb@wizmail.org>
Date: Thu, 26 Mar 2020 16:05:19 +0000
Subject: [PATCH] Fix argument checking for ${readsocket }

---
 doc/doc-txt/ChangeLog        | 3 +++
 src/src/expand.c             | 5 +++--
 test/scripts/0000-Basic/0373 | 4 ++++
 test/stdout/0373             | 2 ++
 4 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog
index be07ba625..7e5de8880 100644
--- a/doc/doc-txt/ChangeLog
+++ b/doc/doc-txt/ChangeLog
@@ -156,6 +156,9 @@ JH/33 Fix the dsearch lookup to return an untainted result.  Previously the
       taint of the lookup key was maintained; we now regard the presence in the
       filesystem as sufficient validation.
 
+JH/34 Fix the readsocket expansion to not segfault when an empty "options"
+      argument is supplied.
+
 
 Exim version 4.93
 -----------------
diff --git a/src/src/expand.c b/src/src/expand.c
index fddad3179..f937ac337 100644
--- a/src/src/expand.c
+++ b/src/src/expand.c
@@ -5335,8 +5335,9 @@ while (*s != 0)
 	uschar * item;
 	int sep = 0;
 
-	item = string_nextinlist(&list, &sep, NULL, 0);
-        if ((timeout = readconf_readtime(item, 0, FALSE)) < 0)
+	if (  !(item = string_nextinlist(&list, &sep, NULL, 0))
+	   || !*item
+	   || (timeout = readconf_readtime(item, 0, FALSE)) < 0)
           {
           expand_string_message = string_sprintf("bad time value %s", item);
           goto EXPAND_FAILED;
diff --git a/test/scripts/0000-Basic/0373 b/test/scripts/0000-Basic/0373
index 02cdc31fc..0f63cee9b 100644
--- a/test/scripts/0000-Basic/0373
+++ b/test/scripts/0000-Basic/0373
@@ -102,3 +102,7 @@ exim -be
 10 >>${readsocket{inet:badloop:PORT_S}{QUERY-10\n}}<<
 11 >>${readsocket{inet:thisloop:PORT_S}{QUERY-11\n}{2s:shutdown=no}}<<
 ****
+#
+exim -be
+crash-regression-check >>${readsocket{inet:127.0.0.1:PORT_N}{}{}}<<
+****
diff --git a/test/stdout/0373 b/test/stdout/0373
index b6f6f1905..a4acc6591 100644
--- a/test/stdout/0373
+++ b/test/stdout/0373
@@ -28,6 +28,8 @@
 > 11 >>ANSWER-11
 <<
 > 
+> Failed: bad time value NULL
+> 
 
 ******** SERVER ********
 Listening on TESTSUITE/test-socket ... 
-- 
2.30.2