# HG changeset patch
# User Bram Moolenaar <Bram@vim.org>
# Date 1666272603 -7200
# Node ID 5bc99d85f773c534d45f2befdd14fc69c0664cac
# Parent  0c6fe9b4ecd1cd6d02ec2c44f3f1ca60334b790a
patch 9.0.0804: crash when trying to divide a number by -1

Commit: https://github.com/vim/vim/commit/cdef1cefa2a440911c727558562f83ed9b00e16b
Author: Bram Moolenaar <Bram@vim.org>
Date:   Thu Oct 20 14:17:18 2022 +0100

    patch 9.0.0804: crash when trying to divide a number by -1

    Problem:    Crash when trying to divice the largest negative number by -1.
    Solution:   Handle this case specifically.

diff --git a/src/eval.c b/src/eval.c
--- a/src/eval.c
+++ b/src/eval.c
@@ -66,6 +66,12 @@ num_divide(varnumber_T n1, varnumber_T n
 	else
 	    result = VARNUM_MAX;
     }
+    else if (n1 == VARNUM_MIN && n2 == -1)
+    {
+	// specific case: trying to do VARNUM_MIN / -1 results in a positive
+	// number that doesn't fit in varnumber_T and causes an FPE
+	result = VARNUM_MAX;
+    }
     else
 	result = n1 / n2;
 
@@ -6023,7 +6029,7 @@ var2fpos(
 }
 
 /*
- * Convert list in "arg" into position "psop" and optional file number "fnump".
+ * Convert list in "arg" into position "posp" and optional file number "fnump".
  * When "fnump" is NULL there is no file number, only 3 items: [lnum, col, off]
  * Note that the column is passed on as-is, the caller may want to decrement
  * it to use 1 for the first column.
diff --git a/src/testdir/test_expr.vim b/src/testdir/test_expr.vim
--- a/src/testdir/test_expr.vim
+++ b/src/testdir/test_expr.vim
@@ -761,6 +761,12 @@ func Test_eval_after_if()
   call assert_equal('b', s:val)
 endfunc
 
+func Test_divide_by_zero()
+  " only tests that this doesn't crash, the result is not important
+  echo 0 / 0
+  echo 0 / 0 / -1
+endfunc
+
 " Test for command-line completion of expressions
 func Test_expr_completion()
   CheckFeature cmdline_compl
diff --git a/src/version.c b/src/version.c
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@ static char *(features[]) =
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    804,
+/**/
     803,
 /**/
     802,