openwrt/toolchain/musl/patches/066-fix-swprintf-internal-buffer-state-and-error-handling.patch

From 7442442ccc665641a8827177e8e7ed45bbbd6584 Mon Sep 17 00:00:00 2001
From: Rich Felker <dalias@aerifal.cx>
Date: Mon, 7 Nov 2016 20:39:59 -0500
Subject: fix swprintf internal buffer state and error handling

the swprintf write callback never reset its buffer pointers, so after
its 256-byte buffer filled up, it would keep repeating those bytes
over and over in the output until the destination buffer filled up. it
also failed to set the error indicator for the stream on EILSEQ,
potentially allowing output to continue after the error.
---
 src/stdio/vswprintf.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/stdio/vswprintf.c b/src/stdio/vswprintf.c
index 7d237ba..6eb2f6a 100644
--- a/src/stdio/vswprintf.c
+++ b/src/stdio/vswprintf.c
@@ -24,7 +24,14 @@ static size_t sw_write(FILE *f, const unsigned char *s, size_t l)
 		c->ws++;
 	}
 	*c->ws = 0;
-	return i<0 ? i : l0;
+	if (i < 0) {
+		f->wpos = f->wbase = f->wend = 0;
+		f->flags |= F_ERR;
+		return i;
+	}
+	f->wend = f->buf + f->buf_size;
+	f->wpos = f->wbase = f->buf;
+	return l0;
 }
 
 int vswprintf(wchar_t *restrict s, size_t n, const wchar_t *restrict fmt, va_list ap)
-- 
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