Added test to only use str2float if compiled with +float

Author: acx0

autoload/indent_guides.vim

@@ -182,12 +182,18 @@ function! indent_guides#init_script_vars()
   let s:debug             = g:indent_guides_debug
   let s:indent_levels     = g:indent_guides_indent_levels
   let s:auto_colors       = g:indent_guides_auto_colors
-  let s:change_percent    = g:indent_guides_color_change_percent / str2float("100.0")
   let s:color_hex_pat     = g:indent_guides_color_hex_pattern
   let s:color_hex_bg_pat  = g:indent_guides_color_hex_guibg_pattern
   let s:color_name_bg_pat = g:indent_guides_color_name_guibg_pattern
   let s:start_level       = g:indent_guides_start_level
 
+  " str2float not available in vim versions <= 7.1
+  if has('float')
+    let s:change_percent = g:indent_guides_color_change_percent / str2float('100.0')
+  else
+    let s:change_percent = g:indent_guides_color_change_percent / 100.0
+  endif
+
   if s:debug
     echo 's:indent_size = '       . s:indent_size
     echo 's:guide_size = '        . s:guide_size