From: Rich Felker <dalias@aerifal.cx>
Date: Thu, 30 Aug 2018 04:08:16 +0000 (-0400)
Subject: prevent perror from clobbering stderr's orientation
X-Git-Url: http://nsz.repo.hu/git/?a=commitdiff_plain;h=cff4b910ab210e5c35f768c75c4562b3ae3e86f2;p=musl

prevent perror from clobbering stderr's orientation

this requirement is specified by POSIX.
---

diff --git a/src/stdio/perror.c b/src/stdio/perror.c
index fdcb4d71..d0943f26 100644
--- a/src/stdio/perror.c
+++ b/src/stdio/perror.c
@@ -9,6 +9,11 @@ void perror(const char *msg)
 	char *errstr = strerror(errno);
 
 	FLOCK(f);
+
+	/* Save stderr's orientation and encoding rule, since perror is not
+	 * permitted to change them. */
+	void *old_locale = f->locale;
+	int old_mode = f->mode;
 	
 	if (msg && *msg) {
 		fwrite(msg, strlen(msg), 1, f);
@@ -18,5 +23,8 @@ void perror(const char *msg)
 	fwrite(errstr, strlen(errstr), 1, f);
 	fputc('\n', f);
 
+	f->mode = old_mode;
+	f->locale = old_locale;
+
 	FUNLOCK(f);
 }