vasnprintf: Fix invalid read past end of memory block.

[gnulib.git] / tests / test-sprintf-posix.h

diff --git a/tests/test-sprintf-posix.h b/tests/test-sprintf-posix.h
index e8b8ba8..ded5042 100644 (file)
--- a/tests/test-sprintf-posix.h
+++ b/tests/test-sprintf-posix.h
@@ -3050,4 +3050,50 @@ test_function (int (*my_sprintf) (char *, const char *, ...))
     ASSERT (strcmp (result + 4000, " 99") == 0);
     ASSERT (retval == strlen (result));
   }
+
+  /* Test the support of the %s format directive.  */
+
+  /* To verify that these tests succeed, it is necessary to run them under
+     a tool that checks against invalid memory accesses, such as ElectricFence
+     or "valgrind --tool=memcheck".  */
+  {
+    size_t i;
+
+    for (i = 1; i <= 8; i++)
+      {
+       char *block;
+       char result[5000];
+       int retval;
+
+       block = (char *) malloc (i);
+       memcpy (block, "abcdefgh", i);
+       retval = my_sprintf (result, "%.*s", (int) i, block);
+       ASSERT (memcmp (result, block, i) == 0);
+       ASSERT (result[i] == '\0');
+       ASSERT (retval == strlen (result));
+       free (block);
+      }
+  }
+#if HAVE_WCHAR_T
+  {
+    size_t i;
+
+    for (i = 1; i <= 8; i++)
+      {
+       wchar_t *block;
+       size_t j;
+       char result[5000];
+       int retval;
+
+       block = (wchar_t *) malloc (i * sizeof (wchar_t));
+       for (j = 0; j < i; j++)
+         block[j] = "abcdefgh"[j];
+       retval = my_sprintf (result, "%.*ls", (int) i, block);
+       ASSERT (memcmp (result, "abcdefgh", i) == 0);
+       ASSERT (result[i] == '\0');
+       ASSERT (retval == strlen (result));
+       free (block);
+      }
+  }
+#endif
 }