Fix packing of values at offset 16.

Our bitmask for setting the highest bit to 0 for
0b11100000 (0xef) instead of 0b01111111 (0x7f) so
we would end up setting bit 5 of each offset to
zero. Fix this and expand test coverage by adding
a fake language (tgp) that has this bit set in both
its bytes.

This issue was discovered while adding CTS tests for
"tgl".

Change-Id: Ibb6de03000951c907c252049771039ab7466187a

2 files changed, 27 insertions, 3 deletions

diff --git a/libs/androidfw/ResourceTypes.cpp b/libs/androidfw/ResourceTypes.cpp
index 2c828c1..2f3b1f7 100644
--- a/libs/androidfw/ResourceTypes.cpp
+++ b/libs/androidfw/ResourceTypes.cpp
@@ -1597,9 +1597,9 @@ void ResTable_config::copyFromDeviceNoSwap(const ResTable_config& o) {
       out[0] = in[0];
       out[1] = in[1];
   } else {
-      uint8_t first = (in[0] - base) & 0x00ef;
-      uint8_t second = (in[1] - base) & 0x00ef;
-      uint8_t third = (in[2] - base) & 0x00ef;
+      uint8_t first = (in[0] - base) & 0x007f;
+      uint8_t second = (in[1] - base) & 0x007f;
+      uint8_t third = (in[2] - base) & 0x007f;
 
       out[0] = (0x80 | (third << 2) | (second >> 3));
       out[1] = ((second << 5) | first);
diff --git a/libs/androidfw/tests/ResourceTypes_test.cpp b/libs/androidfw/tests/ResourceTypes_test.cpp
index 4888b4a..139f868 100644
--- a/libs/androidfw/tests/ResourceTypes_test.cpp
+++ b/libs/androidfw/tests/ResourceTypes_test.cpp
@@ -75,6 +75,30 @@ TEST(ResourceTypesTest, ResourceConfig_packAndUnpack3LetterLanguage) {
      EXPECT_EQ(0, out[3]);
 }
 
+TEST(ResourceTypesTest, ResourceConfig_packAndUnpack3LetterLanguageAtOffset16) {
+     ResTable_config config;
+     config.packLanguage("tgp");
+
+     // We had a bug where we would accidentally mask
+     // the 5th bit of both bytes
+     //
+     // packed[0] = 1011 1100
+     // packed[1] = 1101 0011
+     //
+     // which is equivalent to:
+     // 1  [0]   [1]   [2]
+     // 1-01111-00110-10011
+     EXPECT_EQ(0xbc, config.language[0]);
+     EXPECT_EQ(0xd3, config.language[1]);
+
+     char out[4] = { 1, 1, 1, 1};
+     config.unpackLanguage(out);
+     EXPECT_EQ('t', out[0]);
+     EXPECT_EQ('g', out[1]);
+     EXPECT_EQ('p', out[2]);
+     EXPECT_EQ(0, out[3]);
+}
+
 TEST(ResourceTypesTest, ResourceConfig_packAndUnpack3LetterRegion) {
      ResTable_config config;
      config.packRegion("419");