Add file src/share/grabbag/snprintf.c to grabbag library.

Define function flac_snprintf() which has ISO C99 snprintf() behavior
even when compiling with Microsoft Visual Studio, by wrapping the
MSVS snprintf_s() function.

include/share/compat.h

@@ -143,4 +143,14 @@
 #  endif
 #endif /* defined _MSC_VER */
 
+
+/* FLAC needs to compile and work correctly on systems with a norrmal ISO C99
+ * snprintf as well as Microsoft Visual Studio which has an non-standards
+ * conformant snprint_s function.
+ *
+ * This function wraps the MS version to behave more like the the ISO version.
+ */
+
+int flac_snprintf(char *str, size_t size, const char *fmt, ...);
+
 #endif /* FLAC__SHARE__COMPAT_H */

src/share/grabbag/Makefile.am

@@ -10,7 +10,8 @@ libgrabbag_la_SOURCES = \
 	file.c \
 	picture.c \
 	replaygain.c \
-	seektable.c
+	seektable.c \
+	snprintf.c
 
 EXTRA_DIST = \
 	Makefile.lite \

src/share/grabbag/grabbag_static.vcproj

@@ -186,6 +186,10 @@
 				RelativePath=".\seektable.c"
 				>
 			</File>
+			<File
+				RelativePath=".\snprintf.c"
+				>
+			</File>
 		</Filter>
 		<Filter
 			Name="Public Header Files"

src/share/grabbag/snprintf.c

@@ -0,0 +1,73 @@
+/* libFLAC - Free Lossless Audio Codec library
+ * Copyright (C) 2013  Xiph.org Foundation
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * - Neither the name of the Xiph.org Foundation nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#if HAVE_CONFIG_H
+#  include <config.h>
+#endif
+
+#include <stdio.h>
+#include <stdarg.h>
+
+#include "share/compat.h"
+
+/*
+ * FLAC needs to compile and work correctly on systems with a norrmal ISO C99
+ * snprintf as well as Microsoft Visual Studio which has an non-standards
+ * conformant snprint_s function.
+ *
+ * The important difference occurs when the resultant string (plus string
+ * terminator) would have been longer than the supplied size parameter. When
+ * this happens, ISO C's snprintf returns the length of resultant string, but
+ * does not over-write the end of the buffer. MS's snprintf_s in this case
+ * returns -1.
+ *
+ * The _MSC_VER code below attempts to modify the return code for snprintf_s
+ * to something that is more compatible with the behaviour of the ISO C version.
+ */
+
+int
+flac_snprintf(char *str, size_t size, const char *fmt, ...)
+{
+	va_list va;
+	int rc ;
+
+	va_start (va, fmt);
+
+#ifdef _MSC_VER
+	rc = vsnprintf_s (str, size, fmt, va);
+	rc = (rc > 0) ? rc : (size == 0 ? 1024 : size * 2);
+#else
+	rc = vsnprintf (str, size, fmt, va);
+#endif
+	va_end (va);
+
+	return rc;
+}