From de32435a6c4ea0732f407c62664f065995c1f665 Mon Sep 17 00:00:00 2001
From: John Darrington <john@darrington.wattle.id.au>
Date: Thu, 31 Mar 2016 09:19:35 +0200
Subject: [PATCH] Fixed by where pspp would crash if ELSE appeared without a DO
 IF.

Found by zzuf.
---
 src/language/control/do-if.c    |  5 ++++-
 tests/language/control/do-if.at | 22 ++++++++++++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/src/language/control/do-if.c b/src/language/control/do-if.c
index 6b6dc16d4d..83de0e39a3 100644
--- a/src/language/control/do-if.c
+++ b/src/language/control/do-if.c
@@ -124,9 +124,12 @@ int
 cmd_else (struct lexer *lexer UNUSED, struct dataset *ds)
 {
   struct do_if_trns *do_if = ctl_stack_top (&do_if_class);
-  assert (ds == do_if->ds);
+
   if (do_if == NULL || !must_not_have_else (do_if))
     return CMD_CASCADING_FAILURE;
+
+  assert (ds == do_if->ds);
+
   add_else (do_if);
   return CMD_SUCCESS;
 }
diff --git a/tests/language/control/do-if.at b/tests/language/control/do-if.at
index 2136c9b566..c4f9f0e483 100644
--- a/tests/language/control/do-if.at
+++ b/tests/language/control/do-if.at
@@ -58,3 +58,25 @@ AT_CHECK([pspp -O format=csv do-if.sps], [1], [dnl
 do-if.sps:2: error: END IF: This command cannot appear outside DO IF...END IF.
 ])
 AT_CLEANUP
+
+
+
+AT_SETUP([ELSE without DO IF])
+AT_DATA([do-if.sps], [dnl
+DATA lIST NOTABLE LIST /QUA BRA *.
+BEGIN DATA
+4  1
+6  3
+END DATA
+
+ELSE QUA 'A string'.
+
+EXECUTE.
+])
+AT_CHECK([pspp -O format=csv do-if.sps], [1], [dnl
+do-if.sps:7: error: ELSE: This command cannot appear outside DO IF...END IF.
+
+do-if.sps:9: error: Stopping syntax file processing here to avoid a cascade of dependent command failures.
+])
+AT_CLEANUP
+
-- 
2.30.2