Avoid NPE when getting last shutdown reason.

This can be null if there is a file but it's totally empty, and the
switch statement will throw an NPE when switching on a null string
(thanks Java!)

Bug: 38195795
Test: none
Change-Id: I86901e001b088a4a9b14f15c82b763e12d11875f

parent 47bf1b33

services/core/java/com/android/server/power/PowerManagerService.java

+3 −0

Original line number	Diff line number	Diff line
		@@ -4607,6 +4607,9 @@ public final class PowerManagerService extends SystemService
		} catch (IOException e) {
		Slog.e(TAG, "Failed to read last_reboot_reason file", e);
		}
		if (line == null) {
		return PowerManager.SHUTDOWN_REASON_UNKNOWN;
		}
		switch (line) {
		case REASON_SHUTDOWN:
		return PowerManager.SHUTDOWN_REASON_SHUTDOWN;