android: fix base::Time::FromLocalExploded() crash.

base/time/time_posix.cc

Index: base/time/time_posix.cc
diff --git a/base/time/time_posix.cc b/base/time/time_posix.cc
index 5e06ce93cf039fd420549a345915e2d0ffd62bea..e2879e7440ba98645bacf752b4b9ea38b3354c1d 100644
--- a/base/time/time_posix.cc
+++ b/base/time/time_posix.cc
@@ -214,9 +214,29 @@ Time Time::FromExploded(bool is_local, const Exploded& exploded) {
   timestruct.tm_zone   = NULL;  // not a POSIX field, so mktime/timegm ignore
 #endif
 
-  SysTime seconds = SysTimeFromTimeStruct(&timestruct, is_local);
 
   int64 milliseconds;
+  SysTime seconds;
+
+// On older releases of Android, mktime() will sometimes return -1 when given
+// any second after midnight in certain timezones. For more details, see:
+//   http://b.android.com/61137
+#if defined(OS_ANDROID)
+  // SysTimeFromTimeStruct() modifies the input structure, save current value.
+  struct tm timestruct0 = timestruct;
+
+  seconds = SysTimeFromTimeStruct(&timestruct, is_local);
+  if (seconds == -1 && exploded.hour == 0) {
+    // Work-around this by trying to add one hour.
+    timestruct0.tm_hour = 1;
+    seconds = SysTimeFromTimeStruct(&timestruct0, is_local);
+    if (seconds != -1)
+      seconds -= 60 * 60;
+  }
+#else
+  seconds = SysTimeFromTimeStruct(&timestruct, is_local);
+#endif
+
   // Handle overflow.  Clamping the range to what mktime and timegm might
   // return is the best that can be done here.  It's not ideal, but it's better
   // than failing here or ignoring the overflow case and treating each time
@@ -237,14 +257,19 @@ Time Time::FromExploded(bool is_local, const Exploded& exploded) {
     // When representing the most distant time in the future, add in an extra
     // 999ms to avoid the time being less than any other possible value that
     // this function can return.
+
+    // On Android, SysTime is int64, special care must be taken to avoid
+    // overflows.
+    const int64 min_seconds = (sizeof(SysTime) < sizeof(int64))
+                                  ? std::numeric_limits<SysTime>::min()
+                                  : std::numeric_limits<int32_t>::min();

[digit1, 2013/10/17 14:00:27]

I'm still not sure that using INT32_MAX here is sufficient, but apparently this
code is very cautious because it assumes that the client may perform many
computations with the result, so directly returning INT64_MIN/MAX here might not
be a good idea. What do you think about this?

+    const int64 max_seconds = (sizeof(SysTime) < sizeof(int64))
+                                  ? std::numeric_limits<SysTime>::max()
+                                  : std::numeric_limits<int32_t>::max();
     if (exploded.year < 1969) {
-      CHECK(sizeof(SysTime) < sizeof(int64)) << "integer overflow";
-      milliseconds = std::numeric_limits<SysTime>::min();
-      milliseconds *= kMillisecondsPerSecond;
+      milliseconds = min_seconds * kMillisecondsPerSecond;
     } else {
-      CHECK(sizeof(SysTime) < sizeof(int64)) << "integer overflow";
-      milliseconds = std::numeric_limits<SysTime>::max();
-      milliseconds *= kMillisecondsPerSecond;
+      milliseconds = max_seconds * kMillisecondsPerSecond;
       milliseconds += (kMillisecondsPerSecond - 1);
     }
   } else {