Fix hang from parted not exiting. (See issue 380 for details.)

Fix repeated calls to self.ui.combo_drives.setCurrentIndex(0) when refreshing the combo-box.
Wait for command completion when checking tool availability.

scripts/mbusb_gui.py

@@ -160,16 +160,19 @@ class AppGui(qemu.Qemu, Imager, QtWidgets.QMainWindow, Ui_MainWindow):
 		"""
 		self.ui.installed_distros.clear()
 		config.usb_disk = str(self.ui.combo_drives.currentText())
-		config.imager_usb_disk = str(self.ui.combo_drives.currentText())
-
 		if config.usb_disk:
+			# Get the GPT status of the disk and store it on a variable
+			try:
+				usb.gpt_device(config.usb_disk)
+			except Exception as e:
+				QtWidgets.QMessageBox.critical(
+					self, "The disk/partition is not usable.", str(e))
+				self.ui.combo_drives.setCurrentIndex(0)
+				config.usb_disk = str(self.ui.combo_drives.currentText())
 			log("Selected device " + config.usb_disk)
+			config.imager_usb_disk = str(self.ui.combo_drives.currentText())
 			config.usb_details = usb.details(config.usb_disk)
 			self.update_target_info()
-
-			# Get the GPT status of the disk and store it on a variable
-			usb.gpt_device(config.usb_disk)
-
 			self.update_list_box(config.usb_disk)
 			self.ui_update_persistence()
 		else:
@@ -199,7 +202,7 @@ class AppGui(qemu.Qemu, Imager, QtWidgets.QMainWindow, Ui_MainWindow):
 		for device in detected_devices:
 			if all(not device.startswith(d) for d in protected_drives):
 				self.ui.combo_drives.addItem(str(device))
-			self.ui.combo_drives.setCurrentIndex(0)
+		self.ui.combo_drives.setCurrentIndex(0)
 
 	def update_list_box(self, usb_disk):
 		"""

scripts/osdriver.py

@@ -245,6 +245,10 @@ class Windows(Base):
     def multibootusb_host_dir(self):
         return os.path.join(tempfile.gettempdir(), "multibootusb")
 
+    def gpt_device(self, dev_name):
+        partition, disk = wmi_get_drive_info(dev_name)
+        return  partition.Type.startswith('GPT:')
+
 class Linux(Base):
 
     def __init__(self):
@@ -299,6 +303,30 @@ class Linux(Base):
     def multibootusb_host_dir(self):
         return os.path.join(os.path.expanduser('~'), ".multibootusb")
 
+    def gpt_device(self, dev_name):
+        disk_dev = dev_name.rstrip('0123456789')
+        try:
+            cmd = ['parted', disk_dev, '-s', 'print']
+            with open(os.devnull) as devnull:
+                p = subprocess.Popen(cmd, stdout=subprocess.PIPE,
+                                     stderr=subprocess.PIPE, stdin=devnull)
+                _cmd_out, _err_out = p.communicate()
+                p.wait()
+            if p.returncode != 0:
+                lang = os.getenv('LANG')
+                encoding = lang.rsplit('.')[-1] if lang else 'utf-8'
+                raise RuntimeError(str(_err_out, encoding))
+        except subprocess.CalledProcessError as e:
+            raise RuntimeError(str(e) + '\n\n' + stderr)
+        subprocess.check_call(['partprobe', disk_dev])
+        if b'msdos' in _cmd_out:
+            return False
+        if b'gpt' in _cmd_out:
+            return True
+        raise RuntimeError("Disk '%s' is uninitialized and not usable." %
+                           disk_dev)
+
+
 driverClass = {
     'Windows' : Windows,
     'Linux'   : Linux,
@@ -314,6 +342,7 @@ for func_name in [
         'dd_iso_image',
         'find_mounted_partitions_on',
         'multibootusb_host_dir',
+        'gpt_device',
         ]:
     globals()[func_name] = getattr(osdriver, func_name)
 

scripts/persistence.py

@@ -190,7 +190,8 @@ def detect_missing_tools(distro):
     try:
         with open(os.devnull) as devnull:
             for tool in [e2fsck_exe, resize2fs_exe]:
-                subprocess.Popen([tool], stdout=devnull, stderr=devnull)
+                p = subprocess.Popen([tool], stdout=devnull, stderr=devnull)
+                p.communicate()
     except FileNotFoundError:  # Windows
         return "'%s.exe' is not installed or not available for use." % tool
     except OSError:            # Linux

scripts/usb.py

@@ -397,26 +397,9 @@ def gpt_device(dev_name):
     :param dev_name:
     :return: True if GPT else False
     """
-    if platform.system() == 'Windows':
-        partition, disk = gen.wmi_get_drive_info(dev_name)
-        is_gpt = partition.Type.startswith('GPT:')
-        gen.log('Device %s is a %s disk...' %
-                (dev_name, is_gpt and 'GPT' or 'MBR'))
-        config.usb_gpt = is_gpt
-        return is_gpt
-    if platform.system() == "Linux":
-        if gen.has_digit(dev_name):
-            _cmd_out = subprocess.check_output("parted  " + dev_name[:-1] + " print", shell=True)
-        else:
-            _cmd_out = subprocess.check_output("parted  " + dev_name + " print", shell=True)
-        if b'msdos' in _cmd_out:
-            config.usb_gpt = False
-            gen.log('Device ' + dev_name + ' is a MBR disk...')
-            return False
-        elif b'gpt' in _cmd_out:
-            config.usb_gpt = True
-            gen.log('Device ' + dev_name + ' is a GPT disk...')
-            return True
+    is_gpt = osdriver.gpt_device(dev_name)
+    config.usb_gpt = is_gpt
+    gen.log('Device %s is a %s disk.' % (dev_name, is_gpt and 'GPT' or 'MBR'))
 
 
 def unmount(usb_disk):