[PATCH] pygrub: fix non-interactive parsing of grub1 config files

[Simon Rowe <simon.rowe@eu.citrix.com>]

Changes to handle non-numeric default attributes for grub2 caused run_grub()
to attempt to index into the images list using a string. Pull out the code
that handles submenus into a new function and use that to ensure sel is
numeric.

Reported-by: David Scott <dave.scott@citrix.com>
Signed-off-by: Simon Rowe <simon.rowe@eu.citrix.com>
---
 tools/pygrub/src/pygrub |   23 ++++++++++++++---------
 1 file changed, 14 insertions(+), 9 deletions(-)

diff --git a/tools/pygrub/src/pygrub b/tools/pygrub/src/pygrub
index 1ae34a2..4cc846f 100644
--- a/tools/pygrub/src/pygrub
+++ b/tools/pygrub/src/pygrub
@@ -456,11 +456,9 @@ class Grub:
         del f
         self.cf.parse(buf)
 
-    def run(self):
-        timeout = int(self.cf.timeout)
-
+    def image_index(self):
         if self.cf.default.isdigit():
-            self.selected_image = int(self.cf.default)
+            sel = int(self.cf.default)
         else:
             # We don't fully support submenus. Look for the leaf value in
             # "submenu0>submenu1>...>menuentry" and hope that it's unique.
@@ -472,16 +470,23 @@ class Grub:
                     break
 
             # Map string to index in images array
-            self.selected_image = 0
+            sel = 0
             for i in range(len(self.cf.images)):
                 if self.cf.images[i].title == title:
-                    self.selected_image = i
+                    sel = i
                     break
 
         # If the selected (default) image doesn't exist we select the first entry
-        if self.selected_image > len(self.cf.images):
+        if sel > len(self.cf.images):
             logging.warning("Default image not found")
-            self.selected_image = 0
+            sel = 0
+
+        return sel
+
+    def run(self):
+        timeout = int(self.cf.timeout)
+        self.selected_image = self.image_index()
+
         self.isdone = False
         while not self.isdone:
             self.run_main(timeout)
@@ -626,7 +631,7 @@ def run_grub(file, entry, fs, cfg_args):
     if interactive and not list_entries:
         curses.wrapper(run_main)
     else:
-        sel = g.cf.default
+        sel = g.image_index()
 
     # set the entry to boot as requested
     if entry is not None:
-- 
1.7.10.4