diff --git a/core/product_config.mk b/core/product_config.mk
index 35f018d..540289a 100644
--- a/core/product_config.mk
+++ b/core/product_config.mk
@@ -210,7 +210,6 @@
 # Dedup, extract product names, etc.
 product_paths := $(sort $(product_paths))
 all_named_products := $(sort $(call _first,$(product_paths),:))
-all_product_makefiles := $(sort $(call _second,$(product_paths),:))
 current_product_makefile := $(call _second,$(filter $(TARGET_PRODUCT):%,$(product_paths)),:)
 COMMON_LUNCH_CHOICES := $(sort $(common_lunch_choices))
 
@@ -273,8 +272,6 @@
 ############################################################################
 
 current_product_makefile :=
-all_product_makefiles :=
-all_product_configs :=
 
 #############################################################################
 # Quick check and assign default values
diff --git a/core/product_config.rbc b/core/product_config.rbc
index f67ba8e..7a5e501 100644
--- a/core/product_config.rbc
+++ b/core/product_config.rbc
@@ -619,6 +619,12 @@
         return ""
     return input[l-1]
 
+def _flatten_2d_list(list):
+    result = []
+    for x in list:
+        result += x
+    return result
+
 def _dir(paths):
     """Equivalent to the GNU make function $(dir).
 
@@ -785,7 +791,7 @@
     if t == "list":
         s = " ".join(s)
     elif t != "string":
-        fail("Argument to mkstrip must be a string or list.")
+        fail("Argument to mkstrip must be a string or list, got: "+t)
     result = ""
     was_space = False
     for ch in s.strip().elems():
@@ -879,6 +885,7 @@
     findstring = _findstring,
     first_word = _first_word,
     last_word = _last_word,
+    flatten_2d_list = _flatten_2d_list,
     inherit = _inherit,
     indirect = _indirect,
     mk2rbc_error = _mk2rbc_error,
diff --git a/finalize_branch_for_release.sh b/finalize_branch_for_release.sh
index 8587b3a..c942eb2 100755
--- a/finalize_branch_for_release.sh
+++ b/finalize_branch_for_release.sh
@@ -17,8 +17,7 @@
 # Update references in the codebase to new API version (TODO)
 # ...
 
-# Adding -j1 option because of file(Android.bp) race condition.
-AIDL_TRANSITIVE_FREEZE=true m aidl-freeze-api -j1
+AIDL_TRANSITIVE_FREEZE=true m aidl-freeze-api
 
 m check-vndk-list || update-vndk-list.sh # for new versions of AIDL interfaces
 
diff --git a/tests/run.rbc b/tests/run.rbc
index 107be09..c6dfeba 100644
--- a/tests/run.rbc
+++ b/tests/run.rbc
@@ -43,7 +43,7 @@
 
 assert_eq("", rblf.mkstrip(" \n \t    "))
 assert_eq("a b c", rblf.mkstrip("  a b   \n  c \t"))
-assert_eq(1, rblf.mkstrip(1))
+assert_eq("1", rblf.mkstrip("1 "))
 
 assert_eq("b1 b2", rblf.mksubst("a", "b", "a1 a2"))
 assert_eq(["b1", "x2"], rblf.mksubst("a", "b", ["a1", "x2"]))
@@ -90,6 +90,10 @@
 assert_eq("", rblf.last_word(""))
 assert_eq("", rblf.last_word([]))
 
+assert_eq(["foo", "bar"], rblf.flatten_2d_list([["foo", "bar"]]))
+assert_eq(["foo", "bar"], rblf.flatten_2d_list([["foo"], ["bar"]]))
+assert_eq([], rblf.flatten_2d_list([]))
+
 assert_eq(
     ["build/make/tests/board.rbc", "build/make/tests/board_input_vars.rbc"],
     rblf.expand_wildcard("build/make/tests/board*.rbc")
diff --git a/tools/releasetools/ota_from_target_files.py b/tools/releasetools/ota_from_target_files.py
index c55631b..5384699 100755
--- a/tools/releasetools/ota_from_target_files.py
+++ b/tools/releasetools/ota_from_target_files.py
@@ -1068,10 +1068,11 @@
         pre_partition_state, post_partition_state):
   assert pre_partition_state is not None
   partition_timestamps = {}
-  for part in pre_partition_state:
-    partition_timestamps[part.partition_name] = part.version
   for part in post_partition_state:
-    partition_timestamps[part.partition_name] = \
+    partition_timestamps[part.partition_name] = part.version
+  for part in pre_partition_state:
+    if part.partition_name in partition_timestamps:
+      partition_timestamps[part.partition_name] = \
         max(part.version, partition_timestamps[part.partition_name])
   return [
       "--partition_timestamps",