Set shiftwidth to 0 (defaults to tabstop value)

The current behavior is to set both shiftwidth and tabstop/softtabstop.
shiftwidth gets set to the same value as tabstop. If I open a file that
editorconfig indents with 8-space hard tabs, then ":set tabstop=4", my
shiftwidth will still be 8, meaning that when I indent I will get two
tabs. Set shiftwidth to 0, which defaults to the value of tabstop, and
doesn't set softtabstop either. This should have the same end result
with less complication.

This removes the g:EditorConfig_softtabstop_space and
g:EditorConfig_softtabstop_tab options, as we now don't need to touch
softtabstop at all.

doc/editorconfig.txt

@@ -173,23 +173,6 @@ max_line_length is set:
 <
 This option defaults to 0.
 
-                                            *g:EditorConfig_softtabstop_space*
-When spaces are used for indent, Vim's 'softtabstop' feature will make the
-backspace key delete one indent level. If you turn off that feature (by
-setting the option to 0), only a single space will be deleted.
-This option defaults to 1, which enables 'softtabstop' and uses the
-'shiftwidth' value for it. You can also set this to -1 to automatically follow
-the current 'shiftwidth' value (since Vim 7.3.693). Or set this to [] if
-EditorConfig should not touch 'softtabstop' at all.
-
-                                            *g:EditorConfig_softtabstop_tab*
-When tabs are used for indent, Vim's 'softtabstop' feature only applies to
-backspacing over existing runs of spaces.
-This option defaults to 1, so backspace will delete one indent level worth of
-spaces; -1 does the same but automatically follows the current 'shiftwidth'
-value. Set this to 0 to have backspace delete just a single space character.
-Or set this to [] if EditorConfig should not touch 'softtabstop' at all.
-
                                             *g:EditorConfig_verbose*
 Set this to 1 if you want debug info printed:
 >

plugin/editorconfig.vim

@@ -64,14 +64,6 @@ if !exists('g:EditorConfig_enable_for_new_buf')
     let g:EditorConfig_enable_for_new_buf = 0
 endif
 
-if !exists('g:EditorConfig_softtabstop_space')
-    let g:EditorConfig_softtabstop_space = 1
-endif
-
-if !exists('g:EditorConfig_softtabstop_tab')
-    let g:EditorConfig_softtabstop_tab = 1
-endif
-
 " Copy some of the globals into script variables --- changes to these
 " globals won't affect the plugin until the plugin is reloaded.
 if exists('g:EditorConfig_core_mode') && !empty(g:EditorConfig_core_mode)
@@ -395,31 +387,21 @@ function! s:ApplyConfig(config) abort " Set the buffer options {{{1
         endif
     endif
 
-    if s:IsRuleActive('tab_width', a:config)
-        let &l:tabstop = str2nr(a:config["tab_width"])
-    endif
-
     if s:IsRuleActive('indent_size', a:config)
-        " if indent_size is 'tab', set shiftwidth to tabstop;
-        " if indent_size is a positive integer, set shiftwidth to the integer
-        " value
-        if a:config["indent_size"] == "tab"
-            let &l:shiftwidth = &l:tabstop
-            if type(g:EditorConfig_softtabstop_tab) != type([])
-                let &l:softtabstop = g:EditorConfig_softtabstop_tab > 0 ?
-                            \ &l:shiftwidth : g:EditorConfig_softtabstop_tab
-            endif
-        else
+        " When shiftwidth is 0 it uses the value of tabstop
+        let &l:shiftwidth = 0
+        if a:config["indent_size"] != "tab"
             let l:indent_size = str2nr(a:config["indent_size"])
             if l:indent_size > 0
-                let &l:shiftwidth = l:indent_size
-                if type(g:EditorConfig_softtabstop_space) != type([])
-                    let &l:softtabstop = g:EditorConfig_softtabstop_space > 0 ?
-                            \ &l:shiftwidth : g:EditorConfig_softtabstop_space
-                endif
+                let &l:tabstop = l:indent_size
             endif
         endif
+    endif
 
+    if s:IsRuleActive('tab_width', a:config)
+        if a:config["indent_style"] == "tab"
+            let &l:tabstop = str2nr(a:config["tab_width"])
+        endif
     endif
 
     if s:IsRuleActive('end_of_line', a:config) &&

tests/plugin/spec/editorconfig_spec.rb

@@ -35,22 +35,22 @@ def test_instance(vim)
       it '3_space.py' do
         test_editorconfig vim, '3_space.txt',
           expandtab: '1',
-          shiftwidth: '3',
+          shiftwidth: '0',
           tabstop: '3'
       end
     end
 
     it '4_space.py' do
       test_editorconfig vim, '4_space.py',
         expandtab: '1',
-        shiftwidth: '4',
-        tabstop: '8'
+        shiftwidth: '0',
+        tabstop: '4'
     end
 
     it 'space.txt' do
       test_editorconfig vim, 'space.txt',
         expandtab: '1',
-        shiftwidth: vim.echo('&l:tabstop')
+        shiftwidth: '0'
     end
 
     it 'tab.txt' do
@@ -61,14 +61,14 @@ def test_instance(vim)
     it '4_tab.txt' do
       test_editorconfig vim, '4_tab.txt',
         expandtab: '0',
-        shiftwidth: '4',
+        shiftwidth: '0',
         tabstop: '4'
     end
 
     it '4_tab_width_of_8' do
       test_editorconfig vim, '4_tab_width_of_8.txt',
         expandtab: '0',
-        shiftwidth: '4',
+        shiftwidth: '0',
         tabstop: '8'
     end