Fixed double-fclose when input file is empty.

diff --git a/main.c b/main.c
index c8ea63829b9aac3e193593e55b43f8822f048560..0527595aee3f636c7ac1cecb1fb83884b9de0a4d 100644 (file)
--- a/main.c
+++ b/main.c
@@ -136,6 +136,7 @@ extern FILE* yyout;
 static char outfile_path[MAXLINE];
 static int outfile_created = 0;
 static char *skelname = NULL;
+static int _stdout_closed = 0; /* flag to prevent double-fclose() on stdout. */
 
 /* For debugging. The max number of filters to apply to skeleton. */
 static int preproc_level = 1000;
@@ -158,8 +159,10 @@ int flex_main (argc, argv)
         */
        exit_status = setjmp (flex_main_jmp_buf);
        if (exit_status){
-        fflush(stdout);
-        fclose(stdout);
+        if (stdout && !_stdout_closed && !ferror(stdout)){
+            fflush(stdout);
+            fclose(stdout);
+        }
         while (wait(0) > 0){
         }
                return exit_status - 1;
@@ -683,7 +686,7 @@ void flexend (exit_status)
                        lerrsf (_("error writing output file %s"),
                                outfilename);
 
-               else if (fclose (stdout))
+               else if ((_stdout_closed = 1) && fclose (stdout))
                        lerrsf (_("error closing output file %s"),
                                outfilename);