Reduce startup time by avoiding calling slow au!

autoload/polyglot/detect.vim

@@ -185,7 +185,7 @@ func! polyglot#detect#Pm()
     let &ft = g:filetype_pm | return
   endif
   if polyglot#shebang#Detect() | return | endif
-  set ft=perl | au! BufWritePost <buffer> ++once call polyglot#detect#Pm()
+  set ft=perl | au BufWritePost <buffer> ++once call polyglot#detect#Pm()
   return
 endfunc
 
@@ -207,7 +207,7 @@ func! polyglot#detect#Pl()
     let &ft = g:filetype_pl | return
   endif
   if polyglot#shebang#Detect() | return | endif
-  set ft=perl | au! BufWritePost <buffer> ++once call polyglot#detect#Pl()
+  set ft=perl | au BufWritePost <buffer> ++once call polyglot#detect#Pl()
   return
 endfunc
 
@@ -231,7 +231,7 @@ func! polyglot#detect#T()
     let &ft = g:filetype_t | return
   endif
   if polyglot#shebang#Detect() | return | endif
-  set ft=perl | au! BufWritePost <buffer> ++once call polyglot#detect#T()
+  set ft=perl | au BufWritePost <buffer> ++once call polyglot#detect#T()
   return
 endfunc
 
@@ -259,6 +259,6 @@ func! polyglot#detect#Html()
       set ft=xhtml | return
     endif
   endfor
-  set ft=html | au! BufWritePost <buffer> ++once call polyglot#detect#Html()
+  set ft=html | au BufWritePost <buffer> ++once call polyglot#detect#Html()
   return
 endfunc

scripts/build

@@ -395,7 +395,7 @@ def rule_to_code(rule)
   if rule.has_key?("filetype")
     if rule.has_key?("fallback")
       return <<~EOS
-        set ft=#{rule["filetype"]} | au! BufWritePost <buffer> ++once call polyglot#detect##{camelize(rule["extensions"].first)}()
+        set ft=#{rule["filetype"]} | au BufWritePost <buffer> ++once call polyglot#detect##{camelize(rule["extensions"].first)}()
         return
       EOS
     end
@@ -564,7 +564,7 @@ def generate_ftdetect(packages, heuristics)
       end
 
       if set_globs.size > 0
-        autocommands << "  au! BufNewFile,BufRead #{set_globs.join(",")} #{set_command}\n"
+        autocommands << "  au BufNewFile,BufRead #{set_globs.join(",")} #{set_command}\n"
       end
     end
 
@@ -583,13 +583,13 @@ def generate_ftdetect(packages, heuristics)
 
   show_warnings(all_filetypes, expected_filetypes)
 
-  ftdetect = File.read('ftdetect/polyglot.vim')
+  ftdetect = File.read('filetype.vim')
 
   starting = '" DO NOT EDIT CODE BELOW, IT IS GENERATED WITH MAKEFILE'
   ending = '" DO NOT EDIT CODE ABOVE, IT IS GENERATED WITH MAKEFILE'
 
   File.write(
-    'ftdetect/polyglot.vim',
+    'filetype.vim',
     ftdetect.gsub(/(?<=#{starting}\n)(.*)(?=#{ending})/m) { output }
   )
 

tests/extensions.vim

@@ -30,6 +30,7 @@ call TestExtension("sh", "bash3", "#! /bin/bash2.3")
 call TestExtension("sh", "bash4", "#!/usr/bin/env bash")
 call TestExtension("sh", "bash6", "#!/usr/bin/env -i -=split-string foo=bar bash -l foo")
 call TestExtension("sh", "bash1", "#!/bin/bash")
+" This is defined only by vim-native scripts.vim for now
 call TestExtension("sh", "bash7", ":")
 
 " Vim help file