From f5ed661f729079b4231f9ea1d836b4eb474c5629 Mon Sep 17 00:00:00 2001
From: Tom Cherry <tomcherry@google.com>
Date: Tue, 19 Dec 2017 15:46:07 -0800
Subject: [PATCH] Only apply match if there is something to apply

It is possible for a match to only contain a context and not a schema,
or vice versa and in this case, the previously matched values should
continue to be used.  The serializer already handles this case by
setting the index of the match to ~0u if there is not one, so this
change simply has the parser skip these values.

Bug: 70858511
Test: unit tests, including new ones
Change-Id: Ibc65bd8d637e39f3b1ce7bcc2b88189b75173f88
---
 .../property_info_parser.cpp                  | 24 +++++++++--
 .../property_info_serializer_test.cpp         | 42 +++++++++++++++++++
 2 files changed, 62 insertions(+), 4 deletions(-)

diff --git a/property_service/libpropertyinfoparser/property_info_parser.cpp b/property_service/libpropertyinfoparser/property_info_parser.cpp
index e53c6253e..a8f663624 100644
--- a/property_service/libpropertyinfoparser/property_info_parser.cpp
+++ b/property_service/libpropertyinfoparser/property_info_parser.cpp
@@ -96,8 +96,12 @@ void PropertyInfoArea::CheckPrefixMatch(const char* remaining_name, const TrieNo
     if (prefix_len > remaining_name_size) continue;
 
     if (!strncmp(c_string(trie_node.prefix(i)->name_offset), remaining_name, prefix_len)) {
-      *context_index = trie_node.prefix(i)->context_index;
-      *schema_index = trie_node.prefix(i)->schema_index;
+      if (trie_node.prefix(i)->context_index != ~0u) {
+        *context_index = trie_node.prefix(i)->context_index;
+      }
+      if (trie_node.prefix(i)->schema_index != ~0u) {
+        *schema_index = trie_node.prefix(i)->schema_index;
+      }
       return;
     }
   }
@@ -142,8 +146,20 @@ void PropertyInfoArea::GetPropertyInfoIndexes(const char* name, uint32_t* contex
   // Check exact matches
   for (uint32_t i = 0; i < trie_node.num_exact_matches(); ++i) {
     if (!strcmp(c_string(trie_node.exact_match(i)->name_offset), remaining_name)) {
-      if (context_index != nullptr) *context_index = trie_node.exact_match(i)->context_index;
-      if (schema_index != nullptr) *schema_index = trie_node.exact_match(i)->schema_index;
+      if (context_index != nullptr) {
+        if (trie_node.exact_match(i)->context_index != ~0u) {
+          *context_index = trie_node.exact_match(i)->context_index;
+        } else {
+          *context_index = return_context_index;
+        }
+      }
+      if (schema_index != nullptr) {
+        if (trie_node.exact_match(i)->schema_index != ~0u) {
+          *schema_index = trie_node.exact_match(i)->schema_index;
+        } else {
+          *schema_index = return_schema_index;
+        }
+      }
       return;
     }
   }
diff --git a/property_service/libpropertyinfoserializer/property_info_serializer_test.cpp b/property_service/libpropertyinfoserializer/property_info_serializer_test.cpp
index b3fae268e..46c2d06ef 100644
--- a/property_service/libpropertyinfoserializer/property_info_serializer_test.cpp
+++ b/property_service/libpropertyinfoserializer/property_info_serializer_test.cpp
@@ -844,5 +844,47 @@ TEST(propertyinfoserializer, GetPropertyInfo_prefix_with_dot_vs_without) {
   EXPECT_STREQ("3rd", schema);
 }
 
+TEST(propertyinfoserializer, GetPropertyInfo_empty_context_and_schema) {
+  auto property_info = std::vector<PropertyInfoEntry>{
+      {"persist.", "1st", "", false},
+      {"persist.dot_prefix.", "2nd", "", false},
+      {"persist.non_dot_prefix", "3rd", "", false},
+      {"persist.exact_match", "", "", true},
+      {"persist.dot_prefix2.", "", "4th", false},
+      {"persist.non_dot_prefix2", "", "5th", false},
+  };
+
+  auto serialized_trie = std::string();
+  auto build_trie_error = std::string();
+  ASSERT_TRUE(BuildTrie(property_info, "default", "default", &serialized_trie, &build_trie_error))
+      << build_trie_error;
+
+  auto property_info_area = reinterpret_cast<const PropertyInfoArea*>(serialized_trie.data());
+
+  const char* context;
+  const char* schema;
+  property_info_area->GetPropertyInfo("notpersist.radio.something", &context, &schema);
+  EXPECT_STREQ("default", context);
+  EXPECT_STREQ("default", schema);
+  property_info_area->GetPropertyInfo("persist.nomatch", &context, &schema);
+  EXPECT_STREQ("1st", context);
+  EXPECT_STREQ("default", schema);
+  property_info_area->GetPropertyInfo("persist.dot_prefix.something", &context, &schema);
+  EXPECT_STREQ("2nd", context);
+  EXPECT_STREQ("default", schema);
+  property_info_area->GetPropertyInfo("persist.non_dot_prefix.something", &context, &schema);
+  EXPECT_STREQ("3rd", context);
+  EXPECT_STREQ("default", schema);
+  property_info_area->GetPropertyInfo("persist.exact_match", &context, &schema);
+  EXPECT_STREQ("1st", context);
+  EXPECT_STREQ("default", schema);
+  property_info_area->GetPropertyInfo("persist.dot_prefix2.something", &context, &schema);
+  EXPECT_STREQ("1st", context);
+  EXPECT_STREQ("4th", schema);
+  property_info_area->GetPropertyInfo("persist.non_dot_prefix2.something", &context, &schema);
+  EXPECT_STREQ("1st", context);
+  EXPECT_STREQ("5th", schema);
+}
+
 }  // namespace properties
 }  // namespace android