Do only allow machinecode files for selection/printing

CHANGELOG.md

@@ -10,6 +10,11 @@
   Will now log the update commands and their output similar to the Plugin
   Manager install and uninstall dialog.
 
+### Bug Fixes
+
+* It's not possible anymore to select files that are not machinecode files (e.g.
+  GCODE) for printing on the file API.
+
 ## 1.2.2 (2015-06-30)
 
 ### Bug Fixes

src/octoprint/server/api/files.py

@@ -292,6 +292,9 @@ def gcodeFileCommand(filename, target):
 
 	if command == "select":
 		# selects/loads a file
+		if not octoprint.filemanager.valid_file_type(filename, type="machinecode"):
+			return make_response("Cannot select {filename} for printing, not a machinecode file".format(**locals()), 415)
+
 		printAfterLoading = False
 		if "print" in data.keys() and data["print"] in valid_boolean_trues:
 			if not printer.is_operational():