* libc/stdio/nano-vfprintf_i.c (_printf_i): Use Newlib approach to

	handle string that might be not nul-terminated.
	* testsuite/newlib.stdio/nulprintf.c: New test.

3 files changed, 32 insertions, 9 deletions

diff --git a/newlib/ChangeLog b/newlib/ChangeLog
index 0382bbcd7..6fa883321 100644
--- a/newlib/ChangeLog
+++ b/newlib/ChangeLog
@@ -1,3 +1,9 @@
+2014-11-06  Terry Guo  <terry.guo@arm.com>
+
+	* libc/stdio/nano-vfprintf_i.c (_printf_i): Use Newlib approach to
+	handle string that might be not nul-terminated.
+	* testsuite/newlib.stdio/nulprintf.c: New test.
+
 2014-10-29  Jon Turney  <jon.turney@dronecode.org.uk>
 
 	* libc/include/string.h: Correct guard for strcasecmp().
diff --git a/newlib/libc/stdio/nano-vfprintf_i.c b/newlib/libc/stdio/nano-vfprintf_i.c
index b1b0d1d67..b75a142da 100644
--- a/newlib/libc/stdio/nano-vfprintf_i.c
+++ b/newlib/libc/stdio/nano-vfprintf_i.c
@@ -211,15 +211,15 @@ number:
     case 's':
       cp = GET_ARG (N, *ap, char_ptr_t);
       /* Precision gives the maximum number of chars to be written from a
-	 string, and take prec == -1 into consideration.  */
-      if ((u_int)(pdata->size = strlen (cp)) > (u_int)(pdata->prec))
-	pdata->size = pdata->prec;
-      /* Below code is kept for reading.  The check is redundant because
-	 pdata->prec will be set to pdata->size if it is -1 previously.  */
-#if 0
-      if (pdata->prec > pdata->size)
-#endif
-      pdata->prec = pdata->size;
+	 string, and take prec == -1 into consideration.
+	 Use normal Newlib approach here to support case where cp is not
+	 nul-terminated.  */
+      char *p = memchr (cp, 0, pdata->prec);
+
+      if (p != NULL)
+	pdata->prec = p - cp;
+
+      pdata->size = pdata->prec;
       goto non_number_nosign;
     default:
       /* "%?" prints ?, unless ? is NUL.  */
diff --git a/newlib/testsuite/newlib.stdio/nulprintf.c b/newlib/testsuite/newlib.stdio/nulprintf.c
new file mode 100644
index 000000000..5e4131bc4
--- /dev/null
+++ b/newlib/testsuite/newlib.stdio/nulprintf.c
@@ -0,0 +1,17 @@
+/*
+ * Copyright (C) 2014 by ARM Ltd. All rights reserved.
+ *
+ * Permission to use, copy, modify, and distribute this software
+ * is freely granted, provided that this notice is preserved.
+ */
+
+#include <stdio.h>
+#include "check.h"
+
+const char m[8] = {'M','M','M','M','M','M','M','M'};
+
+int main()
+{
+  printf ("%.*s\n", 8, m);
+  exit (0);
+}