commit 808e57e3f3af403f45d44c93da2e275d427f30cf
author Yi Kong <yikong@google.com> Fri Mar 02 11:27:02 2018 -0500
committer Yi Kong <yikong@google.com> Fri Mar 02 18:42:03 2018 +0000
tree a72e65ce5617784ddf2f4b6f752b83976892be76
parent fd42c098130890b86ba4bf7d717a0c16b3874bb4

healthd: Fix negativity check after cast to unsigned enum

mapSysfsString return code is checked for negativity after being casted
to unsigned enum type, which will always be false. This is obviously
unintended behaviour.

Fixes tautological-unsigned-enum-zero-compare warning.

Bug: 72331526
Test: m
Change-Id: Icec76d7a1121cb56fd9d05feb70cede69954c322

healthd/BatteryMonitor.cpp

diff --git a/healthd/BatteryMonitor.cpp b/healthd/BatteryMonitor.cpp
index 08b8b26..fa79d0b 100644
--- a/healthd/BatteryMonitor.cpp
+++ b/healthd/BatteryMonitor.cpp
@@ -143,7 +143,7 @@
 
 BatteryMonitor::PowerSupplyType BatteryMonitor::readPowerSupplyType(const String8& path) {
     std::string buf;
-    BatteryMonitor::PowerSupplyType ret;
+    int ret;
     struct sysfsStringEnumMap supplyTypeMap[] = {
             { "Unknown", ANDROID_POWER_SUPPLY_TYPE_UNKNOWN },
             { "Battery", ANDROID_POWER_SUPPLY_TYPE_BATTERY },
@@ -164,13 +164,13 @@
     if (readFromFile(path, &buf) <= 0)
         return ANDROID_POWER_SUPPLY_TYPE_UNKNOWN;
 
-    ret = (BatteryMonitor::PowerSupplyType)mapSysfsString(buf.c_str(), supplyTypeMap);
+    ret = mapSysfsString(buf.c_str(), supplyTypeMap);
     if (ret < 0) {
         KLOG_WARNING(LOG_TAG, "Unknown power supply type '%s'\n", buf.c_str());
         ret = ANDROID_POWER_SUPPLY_TYPE_UNKNOWN;
     }
 
-    return ret;
+    return static_cast<BatteryMonitor::PowerSupplyType>(ret);
 }
 
 bool BatteryMonitor::getBooleanField(const String8& path) {