[2.2][qemu2] Fix a crash with -no-cache argument

Qemu2 initialization didn't create a temp cache file
for -no-cache, calling the ext4 initialization on an empty
string. That caused a crash

Bug=http://b.android.com/214083

Change-Id: I280384a10da1b32d5901e26f25f58158231c0906

1 files changed, 13 insertions, 2 deletions

diff --git a/android-qemu2-glue/main.cpp b/android-qemu2-glue/main.cpp
index bc967d5c5c..a609f11fda 100755
--- a/android-qemu2-glue/main.cpp
+++ b/android-qemu2-glue/main.cpp
@@ -40,6 +40,7 @@
 #include "android/utils/filelock.h"
 #include "android/utils/tempfile.h"
 #include "android/utils/stralloc.h"
+#include "android/utils/string.h"
 #include "android/utils/win32_cmdline_quote.h"
 
 #include "android/skin/winsys.h"
@@ -636,9 +637,19 @@ extern "C" int main(int argc, char **argv) {
         }
     }
 
+    bool createEmptyCacheFile = false;
 
-    // Create cache partition image if it doesn't exist already.
-    if (!path_exists(hw->disk_cachePartition_path)) {
+    // Make sure there's a temp cache partition if there wasn't a permanent one
+    if (!hw->disk_cachePartition_path ||
+        strcmp(hw->disk_cachePartition_path, "") == 0) {
+        str_reset(&hw->disk_cachePartition_path,
+                  tempfile_path(tempfile_create()));
+        createEmptyCacheFile = true;
+    }
+
+    createEmptyCacheFile |= !path_exists(hw->disk_cachePartition_path);
+
+    if (createEmptyCacheFile) {
         D("Creating empty ext4 cache partition: %s",
           hw->disk_cachePartition_path);
         int ret = android_createEmptyExt4Image(