Merge branch 'PHP-7.1' into PHP-7.2

* PHP-7.1:
  Fixed bug #75178 (bcpowmod() misbehaves for non-integer base or modulus)

1 files changed, 15 insertions, 7 deletions

diff --git a/ext/bcmath/libbcmath/src/raisemod.c b/ext/bcmath/libbcmath/src/raisemod.c
index 84a7321ea7..84788b4770 100644
--- a/ext/bcmath/libbcmath/src/raisemod.c
+++ b/ext/bcmath/libbcmath/src/raisemod.c
@@ -45,7 +45,7 @@
 int
 bc_raisemod (bc_num base, bc_num expo, bc_num mod, bc_num *result, int scale)
 {
-  bc_num power, exponent, parity, temp;
+  bc_num power, exponent, modulus, parity, temp;
   int rscale;
 
   /* Check for correct numbers. */
@@ -55,12 +55,16 @@ bc_raisemod (bc_num base, bc_num expo, bc_num mod, bc_num *result, int scale)
   /* Set initial values.  */
   power = bc_copy_num (base);
   exponent = bc_copy_num (expo);
+  modulus = bc_copy_num (mod);
   temp = bc_copy_num (BCG(_one_));
   bc_init_num(&parity);
 
   /* Check the base for scale digits. */
-  if (base->n_scale != 0)
+  if (power->n_scale != 0)
+    {
       bc_rt_warn ("non-zero scale in base");
+      bc_divide (power, BCG(_one_), &power, 0); /*truncate */
+    }
 
   /* Check the exponent for scale digits. */
   if (exponent->n_scale != 0)
@@ -70,12 +74,15 @@ bc_raisemod (bc_num base, bc_num expo, bc_num mod, bc_num *result, int scale)
     }
 
   /* Check the modulus for scale digits. */
-  if (mod->n_scale != 0)
+  if (modulus->n_scale != 0)
+    {
       bc_rt_warn ("non-zero scale in modulus");
+      bc_divide (modulus, BCG(_one_), &modulus, 0); /*truncate */
+    }
 
   /* Do the calculation. */
-  rscale = MAX(scale, base->n_scale);
-  if ( !bc_compare(mod, BCG(_one_)) )
+  rscale = MAX(scale, power->n_scale);
+  if ( !bc_compare(modulus, BCG(_one_)) )
     {
       temp = bc_new_num (1, scale);
     }
@@ -87,17 +94,18 @@ bc_raisemod (bc_num base, bc_num expo, bc_num mod, bc_num *result, int scale)
 	  if ( !bc_is_zero(parity) )
 	    {
 	      bc_multiply (temp, power, &temp, rscale);
-	      (void) bc_modulo (temp, mod, &temp, scale);
+	      (void) bc_modulo (temp, modulus, &temp, scale);
 	    }
 
 	  bc_multiply (power, power, &power, rscale);
-	  (void) bc_modulo (power, mod, &power, scale);
+	  (void) bc_modulo (power, modulus, &power, scale);
 	}
     }
 
   /* Assign the value. */
   bc_free_num (&power);
   bc_free_num (&exponent);
+  bc_free_num (&modulus);
   bc_free_num (result);
   bc_free_num (&parity);
   *result = temp;