[alacarte] ItemEditor: Fix bad command validation

[Jasper St. Pierre <jstpierre src gnome org>]

commit 665b4715000e4f6b55db0e23ca100c56f3be4455
Author: OmegaPhil <OmegaPhil+GNOME-bugs gmail com>
Date:   Fri Apr 18 08:25:00 2014 -0400

    ItemEditor: Fix bad command validation
    
    When the Exec line has multiple components, we need to parse it
    and only check the first one.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=728372

 Alacarte/ItemEditor.py |   16 +++++++++++++++-
 1 files changed, 15 insertions(+), 1 deletions(-)
---
diff --git a/Alacarte/ItemEditor.py b/Alacarte/ItemEditor.py
index 3b48324..e89c0ff 100644
--- a/Alacarte/ItemEditor.py
+++ b/Alacarte/ItemEditor.py
@@ -179,10 +179,24 @@ class LauncherEditor(ItemEditor):
         self.builder.get_object('name-entry').connect('changed', self.resync_validity)
         self.builder.get_object('exec-entry').connect('changed', self.resync_validity)
 
+    def exec_line_is_valid(self, exec_text):
+        try:
+            # Attempting to parse command - commands are not simply program names or paths... Errors are 
raised for blank or invalid input (e.g. missing closing quote)
+            result = GLib.shell_parse_argv(exec_text)
+            if result[0]:
+                # Parsing succeeded - making sure program (first part of the command) is in the path
+                command = result[1][0]
+                return (GLib.find_program_in_path(command) is not None)
+            else:
+                # Parsing failure, but not reported via raised GError?
+                return False
+        except GLib.GError:
+            return False
+
     def resync_validity(self, *args):
         name_text = self.builder.get_object('name-entry').get_text()
         exec_text = self.builder.get_object('exec-entry').get_text()
-        valid = (name_text != "" and GLib.find_program_in_path(exec_text) is not None)
+        valid = (name_text != "" and self.exec_line_is_valid(exec_text))
         self.builder.get_object('ok').set_sensitive(valid)
 
     def load(self):