Avoid unwanted escaping in :CommandTCommand and :CommandTTag

Also adjusting `:CommandTHistory` to use the same approach, for
consistency.

doc/command-t.txt

@@ -1558,6 +1558,10 @@ master (not yet released)
 - Fix a RangeError on 64-bit Windows (#304, patch from Adrian Keet).
 - Fix issue switching back to previously opened file in another tab (#306).
 - Fix inability to open some help targets with |:CommandTHelp| (#307).
+- Similar to #307, make |:CommandTCommand| work with commands containing
+  special characters.
+- Again similar to #307, prevent special characters in tags from being escaped
+  when using |:CommandTTag|.
 
 5.0.1 (18 August 2017) ~
 

ruby/command-t/lib/command-t/finder/command_finder.rb

@@ -10,9 +10,17 @@ def initialize(options = {})
       end
 
       def open_selection(command, selection, options = {})
+        escaped = VIM.escape_for_single_quotes selection
         ::VIM::command "call feedkeys(':#{selection} ', 'nt')"
       end
 
+      def prepare_selection(selection)
+        # Pass selection through as-is, bypassing path-based stuff that the
+        # controller would otherwise do, like `expand_path`,
+        # `sanitize_path_string` and `relative_path_under_working_directory`.
+        selection
+      end
+
       def flush; end
 
       def name

ruby/command-t/lib/command-t/finder/history_finder.rb

@@ -11,12 +11,17 @@ def initialize(options = {})
       end
 
       def open_selection(command, selection, options = {})
-        # Need to unescape to reverse the work done by `#sanitize_path_string`.
-        unescaped = selection.gsub(/\\(.)/, '\1')
-        escaped = VIM.escape_for_single_quotes unescaped
+        escaped = VIM.escape_for_single_quotes(selection)
         ::VIM::command "call feedkeys('#{@history_type}#{escaped} ', 'nt')"
       end
 
+      def prepare_selection(selection)
+        # Pass selection through as-is, bypassing path-based stuff that the
+        # controller would otherwise do, like `expand_path`,
+        # `sanitize_path_string` and `relative_path_under_working_directory`.
+        selection
+      end
+
       def flush; end
 
       def name

ruby/command-t/lib/command-t/finder/tag_finder.rb

@@ -18,6 +18,13 @@ def open_selection(command, selection, options = {})
         ::VIM::command "silent! tag #{selection} | :normal zz"
       end
 
+      def prepare_selection(selection)
+        # Pass selection through as-is, bypassing path-based stuff that the
+        # controller would otherwise do, like `expand_path`,
+        # `sanitize_path_string` and `relative_path_under_working_directory`.
+        selection
+      end
+
       def flush
         @scanner.flush
       end