am 78cc93ec: Merge "Fix NPE in StrictMode handling." into lmp-dev

* commit '78cc93ec80f5dcc487db697a1f9a545890745847':
  Fix NPE in StrictMode handling.

core/java/android/os/StrictMode.java

@@ -1726,6 +1726,7 @@ public final class StrictMode {
             if (LOG_V) Log.d(TAG, "strict mode violation stacks read from binder call.  i=" + i);
             ViolationInfo info = new ViolationInfo(p, !currentlyGathering);
             if (info.crashInfo.stackTrace != null && info.crashInfo.stackTrace.length() > 10000) {
+                String front = info.crashInfo.stackTrace.substring(256);
                 // 10000 characters is way too large for this to be any sane kind of
                 // strict mode collection of stacks.  We've had a problem where we leave
                 // strict mode violations associated with the thread, and it keeps tacking
@@ -1742,7 +1743,7 @@ public final class StrictMode {
                 // Now report the problem.
                 Slog.wtfStack(TAG, "Stack is too large: numViolations=" + numViolations
                         + " policy=#" + Integer.toHexString(policyMask)
-                        + " front=" + info.crashInfo.stackTrace.substring(256));
+                        + " front=" + front);
                 return;
             }
             info.crashInfo.stackTrace += "# via Binder call with stack:\n" + ourStack;