vim-patch:9.1.0537: signed number detection for CTRL-X/A can be improved (#29590)

Problem:  signed number detection for CTRL-X/A can be improved
          (Chris Patuzzo)
Solution: Add the new "blank" value for the 'nrformat' setting. This
          will make Vim assume a signed number only if there is a blank
          in front of the sign.
          (distobs)

fixes: vim/vim#15033
closes: vim/vim#15110

https://github.com/vim/vim/commit/25ac6d67d92e0adda53b8d44b81c15031643ca1e

Co-authored-by: distobs <cuppotatocake@gmail.com>

1 files changed, 38 insertions, 0 deletions

diff --git a/test/old/testdir/test_increment.vim b/test/old/testdir/test_increment.vim
index 433b2b4471..cf6334747a 100644
--- a/test/old/testdir/test_increment.vim
+++ b/test/old/testdir/test_increment.vim
@@ -841,6 +841,44 @@ func Test_increment_unsigned()
   set nrformats-=unsigned
 endfunc
 
+" Try incrementing/decrementing a number when nrformats contains blank
+func Test_increment_blank()
+  set nrformats+=blank
+
+  " Signed
+  call setline(1, '0')
+  exec "norm! gg0\<C-X>"
+  call assert_equal('-1', getline(1))
+
+  call setline(1, '3')
+  exec "norm! gg010\<C-X>"
+  call assert_equal('-7', getline(1))
+
+  call setline(1, '-0')
+  exec "norm! gg0\<C-X>"
+  call assert_equal("-1", getline(1))
+
+  " Unsigned
+  " NOTE: 18446744073709551615 == 2^64 - 1
+  call setline(1, 'a-18446744073709551615')
+  exec "norm! gg0\<C-A>"
+  call assert_equal('a-18446744073709551615', getline(1))
+
+  call setline(1, 'a-18446744073709551615')
+  exec "norm! gg0\<C-A>"
+  call assert_equal('a-18446744073709551615', getline(1))
+
+  call setline(1, 'a-18446744073709551614')
+  exec "norm! gg08\<C-A>"
+  call assert_equal('a-18446744073709551615', getline(1))
+
+  call setline(1, 'a-1')
+  exec "norm! gg0\<C-A>"
+  call assert_equal('a-2', getline(1))
+
+  set nrformats-=blank
+endfunc
+
 func Test_in_decrement_large_number()
   " NOTE: 18446744073709551616 == 2^64
   call setline(1, '18446744073709551616')