When the stdout stream gets broken, there is no point in reading

any more input files, and it would be misleading to start a parser,
because that would show randomly truncated text.
Instead, print an error message and exit the program.

Issue found by Leah Neukirchen <leah at vuxu dot org>, who was
surprised to see half a manpage when her /tmp/ overflew.

1 files changed, 12 insertions, 1 deletions

diff --git a/main.c b/main.c
index 7f1411a6..5421a77c 100644
--- a/main.c
+++ b/main.c
@@ -1,4 +1,4 @@
-/*	$Id: main.c,v 1.301 2017/07/26 10:21:55 schwarze Exp $ */
+/*	$Id: main.c,v 1.302 2017/08/21 15:42:58 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2012 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2012, 2014-2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -484,6 +484,17 @@ main(int argc, char *argv[])
 				passthrough(resp->file, fd,
 				    conf.output.synopsisonly);
 
+			if (ferror(stdout)) {
+				if (tag_files != NULL) {
+					warn("%s", tag_files->ofn);
+					tag_unlink();
+					tag_files = NULL;
+				} else
+					warn("stdout");
+				rc = MANDOCLEVEL_SYSERR;
+				break;
+			}
+
 			if (argc > 1 && curp.outtype <= OUTT_UTF8) {
 				if (curp.outdata == NULL)
 					outdata_alloc(&curp);