Set default tabstop to 2, but only if not changed

ftdetect/polyglot.vim

@@ -2545,7 +2545,7 @@ if !has_key(s:disabled_packages, 'alsaconf')
 endif
 
 if !has_key(s:disabled_packages, 'conf')
-  au BufNewFile,BufRead *.conf,auto.master,config setf conf
+  au BufNewFile,BufRead *.conf,*/etc/hosts,auto.master,config setf conf
 endif
 
 if !has_key(s:disabled_packages, 'master')
@@ -2634,6 +2634,10 @@ if !has_key(s:disabled_packages, 'autoindent')
   " Code below re-implements sleuth for vim-polyglot
   let g:loaded_sleuth = 1
 
+  if &tabstop == 8
+    let &tabstop = 2
+  endif
+
   func! s:get_shiftwidth(indents) abort
     let shiftwidth = 0
     let max_count = 0
@@ -2657,9 +2661,8 @@ if !has_key(s:disabled_packages, 'autoindent')
     let minindent = 10
     let spaces_minus_tabs = 0
     let lineno = 0
+    let stack = [0]
     let indents = { '2': 0, '3': 0, '4': 0, '6': 0, '8': 0 }
-    let next_indent_lineno = 1
-    let prev_indent = 0
 
     for line in a:lines
       let lineno += 1
@@ -2731,18 +2734,28 @@ if !has_key(s:disabled_packages, 'autoindent')
       if line[0] == "\t"
         let spaces_minus_tabs -= 1
       else
-        let spaces_minus_tabs += 1
+        if line[0] == " "
+          let spaces_minus_tabs += 1
+        endif
         let indent = len(matchstr(line, '^ *'))
-        let indent_inc = abs(indent - prev_indent)
+        while stack[-1] > indent
+          call remove(stack, -1)
+        endwhile
 
-        if indent_inc > 0 && lineno == next_indent_lineno
-          if has_key(indents, indent_inc)
-            let indents[indent_inc] += 1
-          endif
+        let indent_inc = indent - stack[-1]
+
+        if indent_inc == 0 && len(stack) > 1
+          let indent_inc = indent - stack[-2]
         endif
 
-        let next_indent_lineno = lineno + 1
-        let prev_indent = indent
+        if has_key(indents, indent_inc)
+          let indents[indent_inc] += 1
+          let prev_indent = indent
+        endif
+
+        if stack[-1] != indent
+          call add(stack, indent)
+        endif
       endif
     endfor
 
@@ -2757,9 +2770,7 @@ if !has_key(s:disabled_packages, 'autoindent')
     if shiftwidth > 0
       setlocal expandtab
       let &l:shiftwidth=shiftwidth
-      if &tabstop == 8
-        let &l:tabstop=shiftwidth
-      endif
+      let &l:softtabstop=shiftwidth
       return 1
     endif
 
@@ -2771,18 +2782,13 @@ if !has_key(s:disabled_packages, 'autoindent')
       return
     endif
 
-    if &expandtab
-      " Make tabstop to be synchronized with shiftwidth by default
-      " Some plugins are using &shiftwidth directly or accessing &tabstop
-      if &tabstop != 8 || &shiftwidth == 0
-        let &shiftwidth = &tabstop
-      else
-        let &tabstop = &shiftwidth
-      endif
+    " Do not autodetect indent if language sets it
+    if &l:shiftwidth != &g:shiftwidth
+      return
     endif
 
     let b:sleuth_culprit = expand("<afile>:p")
-    if s:guess(getline(1, 64))
+    if s:guess(getline(1, 128))
       return
     endif
     if s:guess(getline(1, 1024))
@@ -2819,12 +2825,6 @@ if !has_key(s:disabled_packages, 'autoindent')
       let level -= 1
     endwhile
 
-    setlocal expandtab
-    let &l:shiftwidth = 2
-    if &tabstop == 8
-      let &l:tabstop = 2
-    endif
-
     let b:sleuth_culprit = "default"
   endfunc
 

packages.yaml

@@ -1958,6 +1958,7 @@ filetypes:
   filenames:
   - auto.master
   - config
+  - '*/etc/hosts'
 ---
 name: b
 remote: vim/vim:runtime