[nasm:nasm-2.12.xx] listing: Don't try to open non-specified listing

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

Commit-ID:  92c02bb50df5a6489b618dd6a687ed8514762ecb
Gitweb:     http://repo.or.cz/w/nasm.git?a=commitdiff;h=92c02bb50df5a6489b618dd6a687ed8514762ecb
Author:     Cyrill Gorcunov <gor...@gm...>
AuthorDate: Fri, 4 Mar 2016 20:44:42 +0300
Committer:  Cyrill Gorcunov <gor...@gm...>
CommitDate: Fri, 4 Mar 2016 20:44:42 +0300

listing: Don't try to open non-specified listing

By default we setup @listname to '\0' and if has
not been specified in command line it is passed
in this form into list_init() which cause

 | [cyrill@uranus nasm.git] ./nasm -felf64 t.asm
 | nasm: error: unable to open listing file `'

So make a proper test here.

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


---
 listing.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/listing.c b/listing.c
index fa85044..46a2cbf 100644
--- a/listing.c
+++ b/listing.c
@@ -128,7 +128,7 @@ static void list_emit(void)
 
 static void list_init(const char *fname)
 {
-    if (!fname) {
+    if (!fname || fname[0] == '\0') {
 	listfp = NULL;
 	return;
     }