deprecate fugitive variable names in favour of scm-agnostic variable names

autoload/airline.vim

@@ -74,9 +74,13 @@ function! airline#update_externals()
         \ ? '%{bufferline#refresh_status()}'.bufferline#get_status_string()
         \ : "%f%m"
   let g:airline_externals_syntastic = g:airline_enable_syntastic && exists('*SyntasticStatuslineFlag') ? '%{SyntasticStatuslineFlag()}' : ''
-  let g:airline_externals_fugitive = g:airline_enable_fugitive ? (exists('*fugitive#head') && strlen(fugitive#head()) > 0
+  let g:airline_externals_branch = g:airline_enable_branch
-        \ ? g:airline_fugitive_prefix.fugitive#head() : exists('*lawrencium#statusline') && strlen(lawrencium#statusline()) > 0
+        \ ? (exists('*fugitive#head') && strlen(fugitive#head()) > 0
-        \ ? g:airline_fugitive_prefix.lawrencium#statusline() : '') : ''
+          \ ? g:airline_branch_prefix.fugitive#head()
+          \ : exists('*lawrencium#statusline') && strlen(lawrencium#statusline()) > 0
+            \ ? g:airline_branch_prefix.lawrencium#statusline()
+            \ : '')
+        \ : ''
 endfunction
 
 function! s:get_section(key)

doc/airline.txt

@@ -51,7 +51,7 @@ values):
 
 * enable/disable fugitive/lawrencium integration
 >
-  let g:airline_enable_fugitive=1
+  let g:airline_enable_branch=1
 <
 
 * enable/disable syntastic integration
@@ -127,7 +127,7 @@ separators, as well as the powerline font glyths.
   let g:airline_linecolumn_prefix = '␊ '
   let g:airline_linecolumn_prefix = '␤ '
   let g:airline_linecolumn_prefix = '¶ '
-  let g:airline_fugitive_prefix = '⎇ '
+  let g:airline_branch_prefix = '⎇ '
   let g:airline_paste_symbol = 'ρ'
   let g:airline_paste_symbol = 'Þ'
   let g:airline_paste_symbol = '∥'
@@ -137,7 +137,7 @@ separators, as well as the powerline font glyths.
   let g:airline_left_alt_sep = ''
   let g:airline_right_sep = ''
   let g:airline_right_alt_sep = ''
-  let g:airline_fugitive_prefix = ' '
+  let g:airline_branch_prefix = ' '
   let g:airline_readonly_symbol = ''
   let g:airline_linecolumn_prefix = ' '
 
@@ -146,7 +146,7 @@ separators, as well as the powerline font glyths.
   let g:airline_left_alt_sep = '⮁'
   let g:airline_right_sep = '⮂'
   let g:airline_right_alt_sep = '⮃'
-  let g:airline_fugitive_prefix = '⭠'
+  let g:airline_branch_prefix = '⭠'
   let g:airline_readonly_symbol = '⭤'
   let g:airline_linecolumn_prefix = '⭡'
 <
@@ -164,7 +164,7 @@ with the usual statusline syntax.
   let g:airline_section_y      (fileencoding, fileformat)
   let g:airline_section_z      (percentage, line number, column number)
 
-  " here is an example of how you could replace the fugitive indicator with
+  " here is an example of how you could replace the branch indicator with
   " the current working directory, followed by the filename.
   let g:airline_section_b = '%{getcwd()}'
   let g:airline_section_c = '%t'

plugin/airline.vim

@@ -8,17 +8,20 @@ function! s:check_defined(variable, default)
     let {a:variable} = a:default
   endif
 endfunction
+if exists('g:airline_enable_fugitive') || exists('g:airline_fugitive_prefix')
+  echom 'The g:airline_enable_fugitive and g:airline_fugitive_prefix variables have been deprecated and renamed to g:airline_enable_branch and g:airline_branch_prefix respectively. Please update your vimrc.'
+endif
 call s:check_defined('g:airline_left_sep', exists('g:airline_powerline_fonts')?"":">")
 call s:check_defined('g:airline_left_alt_sep', exists('g:airline_powerline_fonts')?"":">")
 call s:check_defined('g:airline_right_sep', exists('g:airline_powerline_fonts')?"":"<")
 call s:check_defined('g:airline_right_alt_sep', exists('g:airline_powerline_fonts')?"":"<")
 call s:check_defined('g:airline_enable_bufferline', 1)
-call s:check_defined('g:airline_enable_fugitive', 1)
+call s:check_defined('g:airline_enable_branch', 1)
 call s:check_defined('g:airline_enable_syntastic', 1)
 call s:check_defined('g:airline_detect_iminsert', 0)
 call s:check_defined('g:airline_detect_modified', 1)
 call s:check_defined('g:airline_detect_paste', 1)
-call s:check_defined('g:airline_fugitive_prefix', exists('g:airline_powerline_fonts')?' ':'')
+call s:check_defined('g:airline_branch_prefix', exists('g:airline_powerline_fonts')?' ':'')
 call s:check_defined('g:airline_readonly_symbol', exists('g:airline_powerline_fonts')?'':'RO')
 call s:check_defined('g:airline_linecolumn_prefix', exists('g:airline_powerline_fonts')?' ':':')
 call s:check_defined('g:airline_paste_symbol', (exists('g:airline_powerline_fonts') ? ' ' : '').'PASTE')
@@ -46,7 +49,7 @@ function! s:init()
     call airline#update_externals()
     call airline#load_theme(g:airline_theme)
     call s:check_defined('g:airline_section_a', '%{g:airline_current_mode_text}')
-    call s:check_defined('g:airline_section_b', '%{g:airline_externals_fugitive}')
+    call s:check_defined('g:airline_section_b', '%{g:airline_externals_branch}')
     call s:check_defined('g:airline_section_c', g:airline_externals_bufferline)
     call s:check_defined('g:airline_section_gutter', '')
     call s:check_defined('g:airline_section_x', "%{strlen(&filetype)>0?&filetype:''}")