4 files changed, 34 insertions, 4 deletions
diff --git a/absl/base/BUILD.bazel b/absl/base/BUILD.bazel
index 1a18f5f7..e825de0c 100644
--- a/absl/base/BUILD.bazel
+++ b/absl/base/BUILD.bazel
@@ -47,6 +47,15 @@ cc_library(
 )
 
 cc_library(
+    name = "raw_logging_internal",
+    copts = ABSL_DEFAULT_COPTS,
+    linkopts = ABSL_DEFAULT_LINKOPTS,
+    visibility = [
+        "//absl:__subpackages__",
+    ],
+)
+
+cc_library(
     name = "spinlock_wait",
     srcs = [
         "internal/spinlock_akaros.inc",
diff --git a/absl/base/CMakeLists.txt b/absl/base/CMakeLists.txt
index 8417556c..9ff80738 100644
--- a/absl/base/CMakeLists.txt
+++ b/absl/base/CMakeLists.txt
@@ -34,7 +34,14 @@ absl_cc_library(
     absl::core_headers
   COPTS
     ${ABSL_DEFAULT_COPTS}
-) 
+)
+
+absl_cc_library(
+  NAME
+    raw_logging_internal
+  COPTS
+    ${ABSL_DEFAULT_COPTS}
+)
 
 absl_cc_library(
   NAME
diff --git a/absl/base/config.h b/absl/base/config.h
index 692738e3..181d840e 100644
--- a/absl/base/config.h
+++ b/absl/base/config.h
@@ -375,12 +375,17 @@
 // https://github.com/abseil/abseil-cpp/issues/207 and
 // https://developer.apple.com/documentation/xcode_release_notes/xcode_10_release_notes
 // libc++ spells out the availability requirements in the file
-// llvm-project/libcxx/include/__config.
+// llvm-project/libcxx/include/__config via the #define
+// _LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS.
 #if defined(__APPLE__) && defined(_LIBCPP_VERSION) && \
   ((defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) && \
    __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 101400) || \
   (defined(__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__) && \
-   __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ < 101200))
+   __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ < 120000) || \
+  (defined(__ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__) && \
+   __ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__ < 120000) || \
+  (defined(__ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__) && \
+   __ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__ < 50000))
 #define ABSL_INTERNAL_APPLE_CXX17_TYPES_UNAVAILABLE 1
 #else
 #define ABSL_INTERNAL_APPLE_CXX17_TYPES_UNAVAILABLE 0
diff --git a/absl/strings/escaping_test.cc b/absl/strings/escaping_test.cc
index 6a633cdc..1967975b 100644
--- a/absl/strings/escaping_test.cc
+++ b/absl/strings/escaping_test.cc
@@ -72,6 +72,11 @@ TEST(CEscape, EscapeAndUnescape) {
       EXPECT_TRUE(absl::CUnescape(escaped, &unescaped_str));
       EXPECT_EQ(unescaped_str, original);
 
+      unescaped_str.erase();
+      std::string error;
+      EXPECT_TRUE(absl::CUnescape(escaped, &unescaped_str, &error));
+      EXPECT_EQ(error, "");
+
       // Check in-place unescaping
       std::string s = escaped;
       EXPECT_TRUE(absl::CUnescape(s, &s));
@@ -150,7 +155,8 @@ TEST(CEscape, BasicEscaping) {
 
 TEST(Unescape, BasicFunction) {
   epair tests[] =
-    {{"\\u0030", "0"},
+    {{"", ""},
+     {"\\u0030", "0"},
      {"\\u00A3", "\xC2\xA3"},
      {"\\u22FD", "\xE2\x8B\xBD"},
      {"\\U00010000", "\xF0\x90\x80\x80"},
@@ -173,6 +179,9 @@ TEST(Unescape, BasicFunction) {
     std::string out;
     EXPECT_FALSE(absl::CUnescape(e, &out, &error));
     EXPECT_FALSE(error.empty());
+
+    out.erase();
+    EXPECT_FALSE(absl::CUnescape(e, &out));
   }
 }