Update.

	* libio/vswprintf.c (_IO_vswprintf): Fix return value handling
	which is different from snprintf.
	* libio/tst_swprintf.c: Add tests for too small output buffer.

1 files changed, 43 insertions, 9 deletions

diff --git a/libio/tst_swprintf.c b/libio/tst_swprintf.c
index 67d10a006d..dc16db0a0c 100644
--- a/libio/tst_swprintf.c
+++ b/libio/tst_swprintf.c
@@ -1,42 +1,76 @@
 #include <stdio.h>
 #include <wchar.h>
+#include <sys/types.h>
+
+
+static wchar_t buf[100];
+#define nbuf (sizeof (buf) / sizeof (buf[0]))
+static const struct
+{
+  size_t n;
+  const char *str;
+  ssize_t exp;
+} tests[] =
+  {
+    { nbuf, "hello world", 11 },
+    { 0, "hello world", -1 },
+    { 0, "", -1 },
+    { nbuf, "", 0 }
+  };
 
 int
 main (int argc, char *argv[])
 {
-  wchar_t buf[100];
   int n;
   int result = 0;
 
   puts ("test 1");
-  n = swprintf (buf, sizeof (buf) / sizeof (buf[0]), L"Hello %s", "world");
+  n = swprintf (buf, nbuf, L"Hello %s", "world");
   if (n != 11)
     {
       printf ("incorrect return value: %d instead of 11\n", n);
       result = 1;
     }
-
-  if (wcscmp (buf, L"Hello world") != 0)
+  else if (wcscmp (buf, L"Hello world") != 0)
     {
       printf ("incorrect string: L\"%ls\" instead of L\"Hello world\"\n", buf);
       result = 1;
     }
 
   puts ("test 2");
-  n = swprintf (buf, sizeof (buf) / sizeof (buf[0]), L"Is this >%g< 3.1?",
-		3.1);
+  n = swprintf (buf, nbuf, L"Is this >%g< 3.1?", 3.1);
   if (n != 18)
-{
+    {
       printf ("incorrect return value: %d instead of 18\n", n);
       result = 1;
     }
-
-  if (wcscmp (buf, L"Is this >3.1< 3.1?") != 0)
+  else if (wcscmp (buf, L"Is this >3.1< 3.1?") != 0)
     {
       printf ("incorrect string: L\"%ls\" instead of L\"Is this >3.1< 3.1?\"\n",
 	      buf);
       result = 1;
     }
 
+  for (n = 0; n < sizeof (tests) / sizeof (tests[0]); ++n)
+    {
+      ssize_t res = swprintf (buf, tests[n].n, L"%s", tests[n].str);
+
+      if (tests[n].exp < 0 && res >= 0)
+	{
+	  printf ("swprintf (buf, %Zu, L\"%%s\", \"%s\") expected to fail\n",
+		  tests[n].n, tests[n].str);
+	  result = 1;
+	}
+      else if (tests[n].exp >= 0 && tests[n].exp != res)
+	{
+	  printf ("swprintf (buf, %Zu, L\"%%s\", \"%s\") expected to return %Zd, but got %Zd\n",
+		  tests[n].n, tests[n].str, tests[n].exp, res);
+	  result = 1;
+	}
+      else
+	printf  ("swprintf (buf, %Zu, L\"%%s\", \"%s\") OK\n",
+		 tests[n].n, tests[n].str);
+    }
+
   return result;
 }