Fix a segfault in AudioFlinger.

Check the string returned by a HAL's implementation of get_parameters
for NULL before attempting to make use of it.  That way, we won't
bring down the mediaserver because of a poorly written HAL.

Change-Id: I45f0fd3de003151f98acf32c36c42f58d053f3a0

diff --git a/services/audioflinger/AudioFlinger.cpp b/services/audioflinger/AudioFlinger.cpp
index 765d9b2..dbad3d9 100644 (file)
--- a/services/audioflinger/AudioFlinger.cpp
+++ b/services/audioflinger/AudioFlinger.cpp
@@ -923,7 +923,7 @@ String8 AudioFlinger::getParameters(int ioHandle, const String8& keys)
         for (size_t i = 0; i < mAudioHwDevs.size(); i++) {
             audio_hw_device_t *dev = mAudioHwDevs[i];
             char *s = dev->get_parameters(dev, keys.string());
-            out_s8 += String8(s);
+            out_s8 += String8(s ? s : "");
             free(s);
         }
         return out_s8;