Always select the next higher density bucket when picking resources

This reverts commit 30715f3afc061bd25a5f251554efc56c412d02d5.

Reason for revert: roll forward with fix

Change-Id: I6d63e6fa508501f2d029eeb4647d4d70c152ceb3
Test: ran all previously failing tests locally
Fixes: 183136881

2 files changed, 13 insertions, 13 deletions

diff --git a/libs/androidfw/ResourceTypes.cpp b/libs/androidfw/ResourceTypes.cpp
index cae2d0bc16b3..5e8a623d4205 100644
--- a/libs/androidfw/ResourceTypes.cpp
+++ b/libs/androidfw/ResourceTypes.cpp
@@ -2677,30 +2677,27 @@ bool ResTable_config::isBetterThan(const ResTable_config& o,
                 // DENSITY_ANY is now dealt with. We should look to
                 // pick a density bucket and potentially scale it.
                 // Any density is potentially useful
-                // because the system will scale it.  Scaling down
-                // is generally better than scaling up.
+                // because the system will scale it.  Always prefer
+                // scaling down.
                 int h = thisDensity;
                 int l = otherDensity;
                 bool bImBigger = true;
                 if (l > h) {
-                    int t = h;
-                    h = l;
-                    l = t;
+                    std::swap(l, h);
                     bImBigger = false;
                 }
 
-                if (requestedDensity >= h) {
-                    // requested value higher than both l and h, give h
+                if (h == requestedDensity) {
+                    // This handles the case where l == h == requestedDensity.
+                    // In that case, this and o are equally good so both
+                    // true and false are valid. This preserves previous
+                    // behavior.
                     return bImBigger;
-                }
-                if (l >= requestedDensity) {
+                } else if (l >= requestedDensity) {
                     // requested value lower than both l and h, give l
                     return !bImBigger;
-                }
-                // saying that scaling down is 2x better than up
-                if (((2 * l) - requestedDensity) * h > requestedDensity * requestedDensity) {
-                    return !bImBigger;
                 } else {
+                    // otherwise give h
                     return bImBigger;
                 }
             }
diff --git a/libs/androidfw/tests/Config_test.cpp b/libs/androidfw/tests/Config_test.cpp
index b54915f03c29..698c36f09301 100644
--- a/libs/androidfw/tests/Config_test.cpp
+++ b/libs/androidfw/tests/Config_test.cpp
@@ -75,6 +75,9 @@ TEST(ConfigTest, shouldSelectBestDensity) {
   configs.add(buildDensityConfig(int(ResTable_config::DENSITY_HIGH) + 20));
   ASSERT_EQ(expectedBest, selectBest(deviceConfig, configs));
 
+  configs.add(buildDensityConfig(int(ResTable_config::DENSITY_XHIGH) - 1));
+  ASSERT_EQ(expectedBest, selectBest(deviceConfig, configs));
+
   expectedBest = buildDensityConfig(ResTable_config::DENSITY_XHIGH);
   configs.add(expectedBest);
   ASSERT_EQ(expectedBest, selectBest(deviceConfig, configs));