[nasm:nasm-2.14.xx] preproc: expand_smacro -- Fix nil dereference on error path

[nasm-bot f. C. G. <gor...@gm...>]

Commit-ID:  980dd658b521afe4a688c4195410c4449a8e2468
Gitweb:     http://repo.or.cz/w/nasm.git?a=commitdiff;h=980dd658b521afe4a688c4195410c4449a8e2468
Author:     Cyrill Gorcunov <gor...@gm...>
AuthorDate: Sun, 14 Oct 2018 19:25:32 +0300
Committer:  Cyrill Gorcunov <gor...@gm...>
CommitDate: Sun, 14 Oct 2018 19:25:32 +0300

preproc: expand_smacro -- Fix nil dereference on error path

When error happened earlier we might have a.mac already
handled and set to nil.

https://bugzilla.nasm.us/show_bug.cgi?id=3392508

Signed-off-by: Cyrill Gorcunov <gor...@gm...>


---
 asm/preproc.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/asm/preproc.c b/asm/preproc.c
index 0ceb243..cdf03bc 100644
--- a/asm/preproc.c
+++ b/asm/preproc.c
@@ -4473,7 +4473,9 @@ again:
         }
 
         if (tline->type == TOK_SMAC_END) {
-            tline->a.mac->in_progress = false;
+            /* On error path it might already be dropped */
+            if (tline->a.mac)
+                tline->a.mac->in_progress = false;
             tline = delete_Token(tline);
         } else {
             t = *tail = tline;