Issue #4075: Use OutputDebugStringW in Py_FatalError.

Misc/NEWS

@@ -12,6 +12,8 @@ What's New in Python 2.7 alpha 1
 Core and Builtins
 -----------------
 
+- Issue #4075: Use OutputDebugStringW in Py_FatalError.
+
 - Issue #4797: IOError.filename was not set when _fileio.FileIO failed to open
   file with `str' filename on Windows.
 

Python/pythonrun.c

@@ -22,6 +22,8 @@
 #include <signal.h>
 #endif
 
+#include "malloc.h" /* for alloca */
+
 #ifdef HAVE_LANGINFO_H
 #include <locale.h>
 #include <langinfo.h>
@@ -1628,9 +1630,21 @@ Py_FatalError(const char *msg)
 {
 	fprintf(stderr, "Fatal Python error: %s\n", msg);
 #ifdef MS_WINDOWS
-	OutputDebugString("Fatal Python error: ");
-	OutputDebugString(msg);
-	OutputDebugString("\n");
+	{
+		size_t len = strlen(msg);
+		WCHAR* buffer;
+		size_t i;
+
+		/* Convert the message to wchar_t. This uses a simple one-to-one
+		conversion, assuming that the this error message actually uses ASCII
+		only. If this ceases to be true, we will have to convert. */
+		buffer = alloca( (len+1) * (sizeof *buffer));
+		for( i=0; i<=len; ++i)
+			buffer[i] = msg[i];
+		OutputDebugStringW(L"Fatal Python error: ");
+		OutputDebugStringW(buffer);
+		OutputDebugStringW(L"\n");
+	}
 #ifdef _DEBUG
 	DebugBreak();
 #endif