[2.28 COMMITTED] stdlib/tst-strtod-overflow: Switch to support_blob_repeat

[2.28 COMMITTED] stdlib/tst-strtod-overflow: Switch to support_blob_repeat

[Florian Weimer]

This is another test with an avoidable large memory allocation.

(cherry picked from commit 07da99aad93c9364acb7efdab47c27ba698f6313)

2018-10-30  Florian Weimer  <fweimer@redhat.com>

	* stdlib/tst-strtod-overflow.c (do_test): Switch to
	support_blob_repeat.

diff --git a/stdlib/tst-strtod-overflow.c b/stdlib/tst-strtod-overflow.c
index d14638d68e..dc53c1e521 100644
--- a/stdlib/tst-strtod-overflow.c
+++ b/stdlib/tst-strtod-overflow.c
@@ -19,6 +19,8 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <support/blob_repeat.h>
+#include <support/test-driver.h>
 
 #define EXPONENT "e-2147483649"
 #define SIZE 214748364
@@ -26,21 +28,23 @@
 static int
 do_test (void)
 {
-  char *p = malloc (1 + SIZE + sizeof (EXPONENT));
-  if (p == NULL)
+  struct support_blob_repeat repeat = support_blob_repeat_allocate
+    ("0", 1, 1 + SIZE + sizeof (EXPONENT));
+  if (repeat.size == 0)
     {
-      puts ("malloc failed, cannot test for overflow");
-      return 0;
+      puts ("warning: memory allocation failed, cannot test for overflow");
+      return EXIT_UNSUPPORTED;
     }
+  char *p = repeat.start;
   p[0] = '1';
-  memset (p + 1, '0', SIZE);
   memcpy (p + 1 + SIZE, EXPONENT, sizeof (EXPONENT));
   double d = strtod (p, NULL);
   if (d != 0)
     {
-      printf ("strtod returned wrong value: %a\n", d);
+      printf ("error: strtod returned wrong value: %a\n", d);
       return 1;
     }
+  support_blob_repeat_free (&repeat);
   return 0;
 }