Fix removal of multiple consecutive 'if' nodes

Despite 'if' nodes being flattened before 'if' removal, consecutive 'if'
nodes can still show up for code like the following:

  ...

  if X
  endif

  if X
  endif

  ...

_remove_ifs() failed to remove the second 'if' node, leading to a crash
e.g. when turning on show-all mode in the menuconfig in a menu with such
code (due to the unexpected 'if' node).

Stuff like the above could potentially result from 'osource's with no
matches, though I just spotted the error while looking over the code.

Fix the 'if' removal logic to properly handle consecutive 'if' nodes.

1 files changed, 11 insertions, 11 deletions

diff --git a/kconfiglib.py b/kconfiglib.py
index eae271e..96e6b52 100644
--- a/kconfiglib.py
+++ b/kconfiglib.py
@@ -5822,17 +5822,17 @@ def _remove_ifs(node):
     node.list = cur
 
     while cur:
-        if cur.next and not cur.next.item:
-            # Equivalent to
-            #
-            #   tmp = cur.next.next
-            #   cur.next = tmp
-            #   cur = tmp
-            #
-            # due to tricky Python semantics. The order matters.
-            cur.next = cur = cur.next.next
-        else:
-            cur = cur.next
+        next = cur.next
+        while next and not next.item:
+            next = next.next
+
+        # Equivalent to
+        #
+        #   cur.next = next
+        #   cur = next
+        #
+        # due to tricky Python semantics. The order matters.
+        cur.next = cur = next
 
 def _finalize_choice(node):
     # Finalizes a choice, marking each symbol whose menu node has the choice as