[gentoo-portage-dev] [PATCH] varexpand: fix IndexError (bug 548556)

[Zac Medico]

This handles two cases where varexpand incremented the index without
checking bounds.

X-Gentoo-Bug: 548556
X-Gentoo-Bug-URL: https://bugs.gentoo.org/show_bug.cgi?id=548556
X-Gentoo-forum-thread: https://forums.gentoo.org/viewtopic-t-1016432.html
---
 pym/portage/util/__init__.py | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/pym/portage/util/__init__.py b/pym/portage/util/__init__.py
index 48cd1b7..c0b509b 100644
--- a/pym/portage/util/__init__.py
+++ b/pym/portage/util/__init__.py
@@ -850,8 +850,20 @@ def varexpand(mystring, mydict=None, error_leader=None):
 					continue
 			elif current == "$":
 				pos += 1
+				if pos == length:
+					# shells handle this like \$
+					newstring.append(current)
+					continue
+
 				if mystring[pos] == "{":
 					pos += 1
+					if pos == length:
+						msg = _varexpand_unexpected_eof_msg
+						if error_leader is not None:
+							msg = error_leader() + msg
+						writemsg(msg + "\n", noiselevel=-1)
+						return ""
+
 					braced = True
 				else:
 					braced = False
-- 
2.3.5