vim-patch:9.0.0343: ColorScheme autocommand triggered when colorscheme not found (#20032)

Problem:    ColorScheme autocommand triggered when colorscheme is not found.
            (Romain Lafourcade)
Solution:   Only trigger ColorScheme when loading the colorscheme succeeds.
            (closes vim/vim#11024)
https://github.com/vim/vim/commit/5d09a401ec393dc930e1104ceb38eab34681de64

Most of Test_colorscheme() is applicable to Nvim.

2 files changed, 46 insertions, 1 deletions

diff --git a/src/nvim/highlight_group.c b/src/nvim/highlight_group.c
index ed1f0185b7..da842e9f84 100644
--- a/src/nvim/highlight_group.c
+++ b/src/nvim/highlight_group.c
@@ -632,7 +632,9 @@ int load_colors(char_u *name)
     retval = source_runtime((char *)buf, DIP_START + DIP_OPT);
   }
   xfree(buf);
-  apply_autocmds(EVENT_COLORSCHEME, (char *)name, curbuf->b_fname, false, curbuf);
+  if (retval == OK) {
+    apply_autocmds(EVENT_COLORSCHEME, (char *)name, curbuf->b_fname, false, curbuf);
+  }
 
   recursive = false;
 
diff --git a/src/nvim/testdir/test_gui.vim b/src/nvim/testdir/test_gui.vim
new file mode 100644
index 0000000000..c3f1f3163a
--- /dev/null
+++ b/src/nvim/testdir/test_gui.vim
@@ -0,0 +1,43 @@
+
+func Test_colorscheme()
+  " call assert_equal('16777216', &t_Co)
+
+  let colorscheme_saved = exists('g:colors_name') ? g:colors_name : 'default'
+  let g:color_count = 0
+  augroup TestColors
+    au!
+    au ColorScheme * let g:color_count += 1
+                 \ | let g:after_colors = g:color_count
+                 \ | let g:color_after = expand('<amatch>')
+    au ColorSchemePre * let g:color_count += 1
+                    \ | let g:before_colors = g:color_count
+                    \ | let g:color_pre = expand('<amatch>')
+  augroup END
+
+  colorscheme torte
+  redraw!
+  call assert_equal('dark', &background)
+  call assert_equal(1, g:before_colors)
+  call assert_equal(2, g:after_colors)
+  call assert_equal('torte', g:color_pre)
+  call assert_equal('torte', g:color_after)
+  call assert_equal("\ntorte", execute('colorscheme'))
+
+  let a = substitute(execute('hi Search'), "\n\\s\\+", ' ', 'g')
+  " FIXME: temporarily check less while the colorscheme changes
+  " call assert_match("\nSearch         xxx term=reverse cterm=reverse ctermfg=196 ctermbg=16 gui=reverse guifg=#ff0000 guibg=#000000", a)
+  " call assert_match("\nSearch         xxx term=reverse ", a)
+
+  call assert_fails('colorscheme does_not_exist', 'E185:')
+  call assert_equal('does_not_exist', g:color_pre)
+  call assert_equal('torte', g:color_after)
+
+  exec 'colorscheme' colorscheme_saved
+  augroup TestColors
+    au!
+  augroup END
+  unlet g:color_count g:after_colors g:before_colors
+  redraw!
+endfunc
+
+" vim: shiftwidth=2 sts=2 expandtab