vp9_alloc_context_buffers: clear cm->mi* on failure

this fixes a crash in vp9_dec_setup_mi() via
vp9_init_context_buffers() should decoding continue and the decoder
resyncs on a smaller frame

BUG=b/30593752

Change-Id: I9ce8d94abe89bcd058697e8bd8599690e61bd380
diff --git a/test/invalid_file_test.cc b/test/invalid_file_test.cc
index d5dc840..f3ac4a7 100644
--- a/test/invalid_file_test.cc
+++ b/test/invalid_file_test.cc
@@ -128,6 +128,12 @@
   { 1, "invalid-vp90-03-v3.webm" },
   { 1, "invalid-vp90-2-00-quantizer-11.webm.ivf.s52984_r01-05_b6-.ivf" },
   { 1, "invalid-vp90-2-00-quantizer-11.webm.ivf.s52984_r01-05_b6-z.ivf" },
+// This file will cause a large allocation which is expected to fail in 32-bit
+// environments. Test x86 for coverage purposes as the allocation failure will
+// be in platform agnostic code.
+#if ARCH_X86
+  { 1, "invalid-vp90-2-00-quantizer-63.ivf.kf_65527x61446.ivf" },
+#endif
   { 1, "invalid-vp90-2-12-droppable_1.ivf.s3676_r01-05_b6-.ivf" },
   { 1, "invalid-vp90-2-05-resize.ivf.s59293_r01-05_b6-.ivf" },
   { 1, "invalid-vp90-2-09-subpixel-00.ivf.s20492_r01-05_b6-.v2.ivf" },
diff --git a/test/test-data.mk b/test/test-data.mk
index 05a0885..80af6e3 100644
--- a/test/test-data.mk
+++ b/test/test-data.mk
@@ -742,6 +742,8 @@
 LIBVPX_TEST_DATA-$(CONFIG_VP9_DECODER) += invalid-vp90-2-00-quantizer-11.webm.ivf.s52984_r01-05_b6-.ivf.res
 LIBVPX_TEST_DATA-$(CONFIG_VP9_DECODER) += invalid-vp90-2-00-quantizer-11.webm.ivf.s52984_r01-05_b6-z.ivf
 LIBVPX_TEST_DATA-$(CONFIG_VP9_DECODER) += invalid-vp90-2-00-quantizer-11.webm.ivf.s52984_r01-05_b6-z.ivf.res
+LIBVPX_TEST_DATA-$(CONFIG_VP9_DECODER) += invalid-vp90-2-00-quantizer-63.ivf.kf_65527x61446.ivf
+LIBVPX_TEST_DATA-$(CONFIG_VP9_DECODER) += invalid-vp90-2-00-quantizer-63.ivf.kf_65527x61446.ivf.res
 LIBVPX_TEST_DATA-$(CONFIG_VP9_DECODER) += invalid-vp90-2-03-size-202x210.webm.ivf.s113306_r01-05_b6-.ivf
 LIBVPX_TEST_DATA-$(CONFIG_VP9_DECODER) += invalid-vp90-2-03-size-202x210.webm.ivf.s113306_r01-05_b6-.ivf.res
 LIBVPX_TEST_DATA-$(CONFIG_VP9_DECODER) += invalid-vp90-2-03-size-224x196.webm.ivf.s44156_r01-05_b6-.ivf
diff --git a/test/test-data.sha1 b/test/test-data.sha1
index a4ed174..18a8773 100644
--- a/test/test-data.sha1
+++ b/test/test-data.sha1
@@ -834,3 +834,5 @@
 7739bfca167b1b43fea72f807f01e097b7cb98d8 *vp90-2-21-resize_inter_640x480_7_1-2.webm.md5
 7291af354b4418917eee00e3a7e366086a0b7a10 *vp90-2-21-resize_inter_640x480_7_3-4.webm
 4a18b09ccb36564193f0215f599d745d95bb558c *vp90-2-21-resize_inter_640x480_7_3-4.webm.md5
+a000d568431d07379dd5a8ec066061c07e560b47  invalid-vp90-2-00-quantizer-63.ivf.kf_65527x61446.ivf
+1e75aad3433c5c21c194a7b53fc393970f0a8d7f  invalid-vp90-2-00-quantizer-63.ivf.kf_65527x61446.ivf.res
diff --git a/vp9/common/vp9_alloccommon.c b/vp9/common/vp9_alloccommon.c
index 602fec2..66aa733 100644
--- a/vp9/common/vp9_alloccommon.c
+++ b/vp9/common/vp9_alloccommon.c
@@ -169,6 +169,8 @@
   return 0;
 
 fail:
+  // clear the mi_* values to force a realloc on resync
+  vp9_set_mb_mi(cm, 0, 0);
   vp9_free_context_buffers(cm);
   return 1;
 }