Merge changes Ibdb7dd0b,Iafd3e846

* changes:
  matches_locale no longer accept empty locales in the png file
  Fall back to en-US if localized bitmap is missing for a locale
diff --git a/minui/resources.cpp b/minui/resources.cpp
index 069a495..00d36d5 100644
--- a/minui/resources.cpp
+++ b/minui/resources.cpp
@@ -347,6 +347,10 @@
   // match the locale string without the {script} section.
   // For instance, prefix == "en" matches locale == "en-US", prefix == "sr-Latn" matches locale
   // == "sr-Latn-BA", and prefix == "zh-CN" matches locale == "zh-Hans-CN".
+  if (prefix.empty()) {
+    return false;
+  }
+
   if (android::base::StartsWith(locale, prefix)) {
     return true;
   }
@@ -414,12 +418,18 @@
     __unused int len = row[4];
     char* loc = reinterpret_cast<char*>(&row[5]);
 
-    if (y + 1 + h >= height || matches_locale(loc, locale)) {
+    // We need to include one additional line for the metadata of the localized image.
+    if (y + 1 + h > height) {
+      printf("Read exceeds the image boundary, y %u, h %d, height %u\n", y, h, height);
+      return -8;
+    }
+
+    if (matches_locale(loc, locale)) {
       printf("  %20s: %s (%d x %d @ %d)\n", name, loc, w, h, y);
 
       auto surface = GRSurface::Create(w, h, w, 1);
       if (!surface) {
-        return -8;
+        return -9;
       }
 
       for (int i = 0; i < h; ++i, ++y) {
@@ -428,7 +438,7 @@
       }
 
       *pSurface = surface.release();
-      break;
+      return 0;
     }
 
     for (int i = 0; i < h; ++i, ++y) {
@@ -436,7 +446,7 @@
     }
   }
 
-  return 0;
+  return -10;
 }
 
 void res_free_surface(GRSurface* surface) {
diff --git a/recovery_main.cpp b/recovery_main.cpp
index 38e1db7..37d9da0 100644
--- a/recovery_main.cpp
+++ b/recovery_main.cpp
@@ -373,7 +373,6 @@
     }
 
     if (locale.empty()) {
-      static constexpr const char* DEFAULT_LOCALE = "en-US";
       locale = DEFAULT_LOCALE;
     }
   }
diff --git a/recovery_ui/include/recovery_ui/ui.h b/recovery_ui/include/recovery_ui/ui.h
index d55322c..797e2f0 100644
--- a/recovery_ui/include/recovery_ui/ui.h
+++ b/recovery_ui/include/recovery_ui/ui.h
@@ -27,6 +27,8 @@
 #include <thread>
 #include <vector>
 
+static constexpr const char* DEFAULT_LOCALE = "en-US";
+
 // Abstract class for controlling the user interface during recovery.
 class RecoveryUI {
  public:
diff --git a/recovery_ui/screen_ui.cpp b/recovery_ui/screen_ui.cpp
index 870db62..8230045 100644
--- a/recovery_ui/screen_ui.cpp
+++ b/recovery_ui/screen_ui.cpp
@@ -817,12 +817,22 @@
 
 std::unique_ptr<GRSurface> ScreenRecoveryUI::LoadLocalizedBitmap(const std::string& filename) {
   GRSurface* surface;
-  if (auto result = res_create_localized_alpha_surface(filename.c_str(), locale_.c_str(), &surface);
-      result < 0) {
-    LOG(ERROR) << "Failed to load bitmap " << filename << " (error " << result << ")";
-    return nullptr;
+  auto result = res_create_localized_alpha_surface(filename.c_str(), locale_.c_str(), &surface);
+  if (result == 0) {
+    return std::unique_ptr<GRSurface>(surface);
   }
-  return std::unique_ptr<GRSurface>(surface);
+  // TODO(xunchang) create a error code enum to refine the retry condition.
+  LOG(WARNING) << "Failed to load bitmap " << filename << " for locale " << locale_ << " (error "
+               << result << "). Falling back to use default locale.";
+
+  result = res_create_localized_alpha_surface(filename.c_str(), DEFAULT_LOCALE, &surface);
+  if (result == 0) {
+    return std::unique_ptr<GRSurface>(surface);
+  }
+
+  LOG(ERROR) << "Failed to load bitmap " << filename << " for locale " << DEFAULT_LOCALE
+             << " (error " << result << ")";
+  return nullptr;
 }
 
 static char** Alloc2d(size_t rows, size_t cols) {
diff --git a/tests/unit/locale_test.cpp b/tests/unit/locale_test.cpp
index cdaba0e..c69434c 100644
--- a/tests/unit/locale_test.cpp
+++ b/tests/unit/locale_test.cpp
@@ -27,7 +27,7 @@
   EXPECT_FALSE(matches_locale("en-GB", "en"));
   EXPECT_FALSE(matches_locale("en-GB", "en-US"));
   EXPECT_FALSE(matches_locale("en-US", ""));
-  // Empty locale prefix in the PNG file will match the input locale.
-  EXPECT_TRUE(matches_locale("", "en-US"));
+  // Empty locale prefix in the PNG file should not match the input locale.
+  EXPECT_FALSE(matches_locale("", "en-US"));
   EXPECT_TRUE(matches_locale("sr-Latn", "sr-Latn-BA"));
 }