Let SetEntropySource() fail if called after V8::Initialize().

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index 415bd41bb19496036f3bda9a6c78ac55ec033ecd..5e9cd65d2c206bda763ddf8ce84cb9b238088d7f 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -5181,8 +5181,16 @@ bool v8::V8::Initialize() {
 }
 
 
-void v8::V8::SetEntropySource(EntropySource entropy_source) {
+bool v8::V8::SetEntropySource(EntropySource entropy_source) {
+  // The entropy source must be set before the library is initialized,
+  // as otherwise not all random number generators will pick up the
+  // entropy source and will fall back to weak entropy instead.
+  i::Isolate* isolate = i::Isolate::UncheckedCurrent();
+  if (isolate != NULL && isolate->IsInitialized())

[Dmitry Lomov (no reviews), 2013/09/23 11:24:15]

Looks like this should be isolate == NULL || !isolate->IsInitialized().

[Dmitry Lomov (no reviews), 2013/09/23 11:25:54]

Nevermind.

+    return false;

[Dmitry Lomov (no reviews), 2013/09/23 11:24:15]

I think just returning false will be ignored (also completely useless for user
program - if the function returns false, there is no way for user program to
recover). I think it will make much more sense to assert this (use ApiCheck
function)

[Benedikt Meurer, 2013/09/23 11:36:41]

Done.

+
   i::RandomNumberGenerator::SetEntropySource(entropy_source);
+  return true;
 }