# HG changeset patch
# User Christian Brabandt <cb@256bit.org>
# Date 1502027104 -7200
# Node ID 66b677c77467cc1ba292097ac4405f7adaa4ebbb
# Parent  4adaaa738e577bdc9fa8489ec58eddb21d9ce3f8
patch 8.0.0879: crash when shifting with huge number

commit https://github.com/vim/vim/commit/bae5a17a738d1a3b5c51d9aa5d99e228d3911955
Author: Bram Moolenaar <Bram@vim.org>
Date:   Sun Aug 6 15:42:06 2017 +0200

    patch 8.0.0879: crash when shifting with huge number

    Problem:    Crash when shifting with huge number.
    Solution:   Check for overflow. (Dominique Pelle, closes https://github.com/vim/vim/issues/1945)

diff --git a/src/ops.c b/src/ops.c
--- a/src/ops.c
+++ b/src/ops.c
@@ -396,7 +396,10 @@ shift_block(oparg_T *oap, int amount)
 	return;
 
     /* total is number of screen columns to be inserted/removed */
-    total = amount * p_sw;
+    total = (int)((unsigned)amount * (unsigned)p_sw);
+    if ((total / p_sw) != amount)
+	return; /* multiplication overflow */
+
     oldp = ml_get_curline();
 
     if (!left)
diff --git a/src/testdir/test_visual.vim b/src/testdir/test_visual.vim
--- a/src/testdir/test_visual.vim
+++ b/src/testdir/test_visual.vim
@@ -18,6 +18,14 @@ func Test_block_shift_multibyte()
   q!
 endfunc
 
+func Test_block_shift_overflow()
+  " This used to cause a multiplication overflow followed by a crash.
+  new
+  normal ii
+  exe "normal \<C-V>876543210>"
+  q!
+endfunc
+
 func Test_dotregister_paste()
   new
   exe "norm! ihello world\<esc>"
diff --git a/src/version.c b/src/version.c
--- a/src/version.c
+++ b/src/version.c
@@ -770,6 +770,8 @@ static char *(features[]) =
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    879,
+/**/
     878,
 /**/
     877,