yes: add explicit error check for WIN32

The test script for md5sum uses 'yes $text | head'.  This fails
because of Microsoft Windows' dodgy handling of pipes.  yes checks
the return value of putchar for an error, but on WIN32 none comes
when a pipe fails.  ferror, OTOH, does report an error.

1 files changed, 4 insertions, 0 deletions

diff --git a/coreutils/yes.c b/coreutils/yes.c
index 5d799f09b..c3d3e8288 100644
--- a/coreutils/yes.c
+++ b/coreutils/yes.c
@@ -33,6 +33,10 @@ int yes_main(int argc UNUSED_PARAM, char **argv)
                 ++argv;
 
         do {
+#if ENABLE_PLATFORM_MINGW32
+                if (ferror(stdout) != 0)
+                        break;
+#endif
                 pp = argv;
                 while (1) {
                         fputs(*pp, stdout);