vim-patch:9.1.0557: moving in the buffer list doesn't work as documented (#29653)

Problem:  moving in the buffer list doesn't work as documented
          (SenileFelineS)
Solution: Skip non-help buffers, when run from normal buffers, else
          only move from help buffers to the next help buffer (LemonBoy)

As explained in the help section for :bnext and :bprev the commands
should jump from help buffers to help buffers (and from regular ones to
regular ones).

fixes: vim/vim#4478
closes: vim/vim#15198

https://github.com/vim/vim/commit/893eeeb44583ca33276e263165b2a6e50fd297d0

Co-authored-by: LemonBoy <thatlemon@gmail.com>

1 files changed, 46 insertions, 0 deletions

diff --git a/test/old/testdir/test_buffer.vim b/test/old/testdir/test_buffer.vim
index bc8e5eaf7b..69d22de2ce 100644
--- a/test/old/testdir/test_buffer.vim
+++ b/test/old/testdir/test_buffer.vim
@@ -126,6 +126,52 @@ func Test_buflist_browse()
   %bwipe!
 endfunc
 
+" Test for :bnext and :bprev when called from help and non-help buffers.
+func Test_bnext_bprev_help()
+  %bwipe!
+
+  e XHelp1 | set bt=help
+  let b1 = bufnr()
+  e Xbuf1
+  let b2 = bufnr()
+
+  " There's only one buffer of each type.
+  b XHelp1
+  bnext | call assert_equal(b1, bufnr())
+  bprev | call assert_equal(b1, bufnr())
+  b Xbuf1
+  bnext | call assert_equal(b2, bufnr())
+  bprev | call assert_equal(b2, bufnr())
+
+  " Add one more buffer of each type.
+  e XHelp2 | set bt=help
+  let b3 = bufnr()
+  e Xbuf2
+  let b4 = bufnr()
+
+  " Help buffer jumps to help buffer.
+  b XHelp1
+  bnext | call assert_equal(b3, bufnr())
+  bnext | call assert_equal(b1, bufnr())
+  bprev | call assert_equal(b3, bufnr())
+  bprev | call assert_equal(b1, bufnr())
+
+  " Regular buffer jumps to regular buffer.
+  b Xbuf1
+  bnext | call assert_equal(b4, bufnr())
+  bnext | call assert_equal(b2, bufnr())
+  bprev | call assert_equal(b4, bufnr())
+  bprev | call assert_equal(b2, bufnr())
+
+  " :brewind and :blast are not affected by the buffer type.
+  b Xbuf2
+  brewind | call assert_equal(b1, bufnr())
+  b XHelp1
+  blast   | call assert_equal(b4, bufnr())
+
+  %bwipe!
+endfunc
+
 " Test for :bdelete
 func Test_bdelete_cmd()
   %bwipe!