diff -Naurd mpfr-3.1.5-a/PATCHES mpfr-3.1.5-b/PATCHES
--- mpfr-3.1.5-a/PATCHES	2017-06-06 19:50:30.708438500 +0000
+++ mpfr-3.1.5-b/PATCHES	2017-06-06 19:50:30.736438175 +0000
@@ -0,0 +1 @@
+tests-buffer-size
diff -Naurd mpfr-3.1.5-a/VERSION mpfr-3.1.5-b/VERSION
--- mpfr-3.1.5-a/VERSION	2017-06-06 19:21:17.604843293 +0000
+++ mpfr-3.1.5-b/VERSION	2017-06-06 19:50:30.736438175 +0000
@@ -1 +1 @@
-3.1.5-p3
+3.1.5-p4
diff -Naurd mpfr-3.1.5-a/src/mpfr.h mpfr-3.1.5-b/src/mpfr.h
--- mpfr-3.1.5-a/src/mpfr.h	2017-06-06 19:21:17.600843340 +0000
+++ mpfr-3.1.5-b/src/mpfr.h	2017-06-06 19:50:30.732438221 +0000
@@ -27,7 +27,7 @@
 #define MPFR_VERSION_MAJOR 3
 #define MPFR_VERSION_MINOR 1
 #define MPFR_VERSION_PATCHLEVEL 5
-#define MPFR_VERSION_STRING "3.1.5-p3"
+#define MPFR_VERSION_STRING "3.1.5-p4"
 
 /* Macros dealing with MPFR VERSION */
 #define MPFR_VERSION_NUM(a,b,c) (((a) << 16L) | ((b) << 8) | (c))
diff -Naurd mpfr-3.1.5-a/src/version.c mpfr-3.1.5-b/src/version.c
--- mpfr-3.1.5-a/src/version.c	2017-06-06 19:21:17.604843293 +0000
+++ mpfr-3.1.5-b/src/version.c	2017-06-06 19:50:30.736438175 +0000
@@ -25,5 +25,5 @@
 const char *
 mpfr_get_version (void)
 {
-  return "3.1.5-p3";
+  return "3.1.5-p4";
 }
diff -Naurd mpfr-3.1.5-a/tests/tl2b.c mpfr-3.1.5-b/tests/tl2b.c
--- mpfr-3.1.5-a/tests/tl2b.c	2016-09-27 07:58:14.000000000 +0000
+++ mpfr-3.1.5-b/tests/tl2b.c	2017-06-06 19:50:30.724438314 +0000
@@ -83,7 +83,7 @@
   mpfr_srcptr t;
   int beta, i;
   int error = 0;
-  char buffer[30];
+  char buffer[256];  /* larger than needed, for maintainability */
 
   for (beta = 2; beta <= BASE_MAX; beta++)
     {
diff -Naurd mpfr-3.1.5-a/tests/tpow_all.c mpfr-3.1.5-b/tests/tpow_all.c
--- mpfr-3.1.5-a/tests/tpow_all.c	2016-09-27 07:58:14.000000000 +0000
+++ mpfr-3.1.5-b/tests/tpow_all.c	2017-06-06 19:50:30.724438314 +0000
@@ -498,7 +498,7 @@
   for (i = 0; i <= 12; i++)
     {
       unsigned int flags = 0;
-      char sy[16];
+      char sy[256];  /* larger than needed, for maintainability */
 
       /* Test 2^(emin - i/4).
        * --> Underflow iff i > 4.