Fix relative_to_original_destination_root and better tests

Many broken edge cases were present, such as if a later substring of the path matched the root or if the root only matched a subpart of a directory.

Author: MaxLap

lib/thor/actions.rb

@@ -113,8 +113,10 @@ def destination_root=(root)
     # the script started).
     #
     def relative_to_original_destination_root(path, remove_dot = true)
-      path = path.dup
-      if path.sub!(@destination_stack[0], ".")
+      root = @destination_stack[0]
+      if path.start_with?(root) && [File::SEPARATOR, File::ALT_SEPARATOR, nil, ''].include?(path[root.size..root.size])
+        path = path.dup
+        path[0...root.size] = '.'
         remove_dot ? (path[2..-1] || "") : path
       else
         path

spec/actions_spec.rb

@@ -86,9 +86,19 @@ def file
         expect(runner.relative_to_original_destination_root("/test/file")).to eq("/test/file")
       end
 
+      it "doesn't remove the root path from the absolute path if it is not at the begining" do
+        runner.destination_root = "/app"
+        expect(runner.relative_to_original_destination_root("/something/app/project")).to eq("/something/app/project")
+      end
+
+      it "doesn't removes the root path from the absolute path only if it is only the partial name of the directory" do
+        runner.destination_root = "/app"
+        expect(runner.relative_to_original_destination_root("/application/project")).to eq("/application/project")
+      end
+
       it "removes the root path from the absolute path only once" do
         runner.destination_root = "/app"
-        expect(runner.relative_to_original_destination_root("/app/project/application")).to eq("project/application")
+        expect(runner.relative_to_original_destination_root("/app/app/project")).to eq("app/project")
       end
 
       it "does not fail with files containing regexp characters" do