X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/fe8ab488e9161c46dd9885d58fc52996dc0249ff..ea3f04195ba4a5034c9c8e9b726d4f7ce96f1832:/libsyscall/mach/string.c

diff --git a/libsyscall/mach/string.c b/libsyscall/mach/string.c
index e1555b49d..fcb9e6fd2 100644
--- a/libsyscall/mach/string.c
+++ b/libsyscall/mach/string.c
@@ -2,7 +2,7 @@
  * Copyright (c) 2010 Apple Inc. All rights reserved.
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
- * 
+ *
  * This file contains Original Code and/or Modifications of Original Code
  * as defined in and that are subject to the Apple Public Source License
  * Version 2.0 (the 'License'). You may not use this file except in
@@ -11,10 +11,10 @@
  * unlawful or unlicensed copies of an Apple operating system, or to
  * circumvent, violate, or enable the circumvention or violation of, any
  * terms of an Apple operating system software license agreement.
- * 
+ *
  * Please obtain a copy of the License at
  * http://www.opensource.apple.com/apsl/ and read it before using this file.
- * 
+ *
  * The Original Code and all software distributed under the License are
  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
@@ -22,7 +22,7 @@
  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  * Please see the License for the specific language governing rights and
  * limitations under the License.
- * 
+ *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 
@@ -48,14 +48,14 @@ _mach_hex(char **buffer, int *length, unsigned long long n)
 {
 	char buf[32];
 	char *cp = buf + sizeof(buf);
-	
+
 	if (n) {
 		*--cp = '\0';
 		while (n) {
 			*--cp = hex[n & 0xf];
 			n >>= 4;
 		}
-		
+
 		int width = _mach_strlen(cp);
 		while (width > 0 && length > 0) {
 			*(*buffer)++ = *cp++;
@@ -70,7 +70,7 @@ _mach_vsnprintf(char *buffer, int length, const char *fmt, va_list ap)
 {
 	int width, max = length;
 	char *out_ptr = buffer;
-	
+
 	// we only ever write n-1 bytes so we can put a \0 at the end
 	length--;
 	while (length > 0 && *fmt) {
@@ -86,26 +86,28 @@ _mach_vsnprintf(char *buffer, int length, const char *fmt, va_list ap)
 		// only going to support a specific subset of sprintf flags
 		// namely %s, %x, with no padding modifiers
 		switch (*fmt++) {
-			case 's':
-			{
-				char *cp = va_arg(ap, char*);
-				width = _mach_strlen(cp);
-				while (width > 0 && length > 0) {
-					*(out_ptr++) = *(cp++);
-					width--;
-					length--;
-				}
-				break;
-			}
-			case 'x':
-			{
-				_mach_hex(&out_ptr, &length, va_arg(ap, unsigned int));
-				break;
+		case 's':
+		{
+			char *cp = va_arg(ap, char*);
+			width = _mach_strlen(cp);
+			while (width > 0 && length > 0) {
+				*(out_ptr++) = *(cp++);
+				width--;
+				length--;
 			}
+			break;
+		}
+		case 'x':
+		{
+			_mach_hex(&out_ptr, &length, va_arg(ap, unsigned int));
+			break;
+		}
 		}
 	}
-	*out_ptr = '\0';
-	return max - length;
+	if (max > 0) {
+		*out_ptr = '\0';
+	}
+	return max - (length + 1); /* don't include the final NULL in the return value */
 }
 
 int