From b457a58e34d43d49a01dd93ec356099d232bd713 Mon Sep 17 00:00:00 2001
From: Jan Edmund Lazo <jan.lazo@mail.utoronto.ca>
Date: Sun, 28 Jul 2019 16:54:06 -0400
Subject: vim-patch:8.1.0990: floating point exception with "%= 0" and "/= 0"

Problem:    Floating point exception with "%= 0" and "/= 0".
Solution:   Avoid dividing by zero. (Dominique Pelle, closes vim/vim#4058)
https://github.com/vim/vim/commit/e21c1580b7acb598a6e3c38565434fe5d0e2ad7a
---
 src/nvim/eval.c | 50 +++++++++++++++++++++++++++++++++-----------------
 1 file changed, 33 insertions(+), 17 deletions(-)

(limited to 'src/nvim/eval.c')

diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index b9f5863499..0a1328a2f1 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -526,6 +526,35 @@ const list_T *eval_msgpack_type_lists[] = {
   [kMPExt] = NULL,
 };
 
+// Return "n1" divided by "n2", taking care of dividing by zero.
+varnumber_T num_divide(varnumber_T n1, varnumber_T n2)
+  FUNC_ATTR_CONST FUNC_ATTR_WARN_UNUSED_RESULT
+{
+  varnumber_T result;
+
+  if (n2 == 0) {  // give an error message?
+    if (n1 == 0) {
+      result = VARNUMBER_MIN;  // similar to NaN
+    } else if (n1 < 0) {
+      result = -VARNUMBER_MAX;
+    } else {
+      result = VARNUMBER_MAX;
+    }
+  } else {
+    result = n1 / n2;
+  }
+
+  return result;
+}
+
+// Return "n1" modulus "n2", taking care of dividing by zero.
+varnumber_T num_modulus(varnumber_T n1, varnumber_T n2)
+  FUNC_ATTR_CONST FUNC_ATTR_WARN_UNUSED_RESULT
+{
+  // Give an error when n2 is 0?
+  return (n2 == 0) ? 0 : (n1 % n2);
+}
+
 /*
  * Initialize the global and v: variables.
  */
@@ -2047,8 +2076,8 @@ static char_u *ex_let_one(char_u *arg, typval_T *const tv,
               case '+': n = numval + n; break;
               case '-': n = numval - n; break;
               case '*': n = numval * n; break;
-              case '/': n = numval / n; break;
-              case '%': n = numval % n; break;
+              case '/': n = num_divide(numval, n); break;
+              case '%': n = num_modulus(numval, n); break;
             }
           } else if (opt_type == 0 && stringval != NULL) {  // string
             char *const oldstringval = stringval;
@@ -4178,22 +4207,9 @@ static int eval6(char_u **arg, typval_T *rettv, int evaluate, int want_string)
         if (op == '*') {
           n1 = n1 * n2;
         } else if (op == '/') {
-          if (n2 == 0) {                // give an error message?
-            if (n1 == 0) {
-              n1 = VARNUMBER_MIN;  // similar to NaN
-            } else if (n1 < 0) {
-              n1 = -VARNUMBER_MAX;
-            } else {
-              n1 = VARNUMBER_MAX;
-            }
-          } else {
-            n1 = n1 / n2;
-          }
+          n1 = num_divide(n1, n2);
         } else {
-          if (n2 == 0)                  /* give an error message? */
-            n1 = 0;
-          else
-            n1 = n1 % n2;
+          n1 = num_modulus(n1, n2);
         }
         rettv->v_type = VAR_NUMBER;
         rettv->vval.v_number = n1;
-- 
cgit