commit 1a632def894f8fec6961d126fcc568c6a7c19441
author gaoshang <gaoshang@xiaomi.com> Wed Aug 24 10:23:50 2016 +0800
committer gaoshang <gaoshang@xiaomi.com> Tue Aug 30 08:03:51 2016 +0000
tree 59b2c2762d8c32e3fe08911b4d9743637a25cc3b
parent 1c59b4b4e8447feb25a2e1673ac432310ca4655b

redirect to call assignPointerIds if there is id < 0 case

Symptom: If assignPointerIds() is not called, the unknown value of
outPointer.id will lead to undefined things
Root Cause: mHavePointerIds be overwritten to true in last cycle
Solution: recover mHavePointerIds=false if any id < 0, to call assignPointerIds()

https://code.google.com/p/android/issues/detail?id=221273

Change-Id: I65ca0b82a6fceb495a0de17315b1f49cdab5fba0
Signed-off-by: gaoshang <gaoshang@xiaomi.com>

services/inputflinger/InputReader.cpp

diff --git a/services/inputflinger/InputReader.cpp b/services/inputflinger/InputReader.cpp
index b2cbfe8..449d857 100644
--- a/services/inputflinger/InputReader.cpp
+++ b/services/inputflinger/InputReader.cpp
@@ -6488,6 +6488,7 @@
     size_t inCount = mMultiTouchMotionAccumulator.getSlotCount();
     size_t outCount = 0;
     BitSet32 newPointerIdBits;
+    mHavePointerIds = true;
 
     for (size_t inIndex = 0; inIndex < inCount; inIndex++) {
         const MultiTouchMotionAccumulator::Slot* inSlot =
@@ -6532,33 +6533,33 @@
         outPointer.isHovering = isHovering;
 
         // Assign pointer id using tracking id if available.
-        mHavePointerIds = true;
-        int32_t trackingId = inSlot->getTrackingId();
-        int32_t id = -1;
-        if (trackingId >= 0) {
-            for (BitSet32 idBits(mPointerIdBits); !idBits.isEmpty(); ) {
-                uint32_t n = idBits.clearFirstMarkedBit();
-                if (mPointerTrackingIdMap[n] == trackingId) {
-                    id = n;
+        if (mHavePointerIds) {
+            int32_t trackingId = inSlot->getTrackingId();
+            int32_t id = -1;
+            if (trackingId >= 0) {
+                for (BitSet32 idBits(mPointerIdBits); !idBits.isEmpty(); ) {
+                    uint32_t n = idBits.clearFirstMarkedBit();
+                    if (mPointerTrackingIdMap[n] == trackingId) {
+                        id = n;
+                    }
+                }
+
+                if (id < 0 && !mPointerIdBits.isFull()) {
+                    id = mPointerIdBits.markFirstUnmarkedBit();
+                    mPointerTrackingIdMap[id] = trackingId;
                 }
             }
-
-            if (id < 0 && !mPointerIdBits.isFull()) {
-                id = mPointerIdBits.markFirstUnmarkedBit();
-                mPointerTrackingIdMap[id] = trackingId;
+            if (id < 0) {
+                mHavePointerIds = false;
+                outState->rawPointerData.clearIdBits();
+                newPointerIdBits.clear();
+            } else {
+                outPointer.id = id;
+                outState->rawPointerData.idToIndex[id] = outCount;
+                outState->rawPointerData.markIdBit(id, isHovering);
+                newPointerIdBits.markBit(id);
             }
         }
-        if (id < 0) {
-            mHavePointerIds = false;
-            outState->rawPointerData.clearIdBits();
-            newPointerIdBits.clear();
-        } else {
-            outPointer.id = id;
-            outState->rawPointerData.idToIndex[id] = outCount;
-            outState->rawPointerData.markIdBit(id, isHovering);
-            newPointerIdBits.markBit(id);
-        }
-
         outCount += 1;
     }