In readFromChild() for Windows: Call PeekNamedPipe() to check for available data.

Reason: ReadFile() doesn't always return if there's no data and the child exits after ReadFile()
is called.

child.cpp

@@ -1455,20 +1455,64 @@ namespace CodeDweller {
 
       // Blocking read from the child.
 #ifdef _WIN32
+
       DWORD nBytesRead;
 
-      if (!ReadFile(inputHandle,
-                    bufferPtr,
-                    bufferCapacity,
-                    &nBytesRead,
-                    NULL)) {
+      try {
 
-        if (stopReaderFlag) {
-          break;
-        }
+	DWORD bytesAvailable;
+
+	if (!PeekNamedPipe(inputHandle,
+			   NULL,
+			   0,
+			   NULL,
+			   &bytesAvailable,
+			   NULL)) {
+	  throw std::runtime_error("Error from PeekNamedPipe:  " +
+				   getErrorText());
+	}
+
+	// Is data available?
+	if (0 == bytesAvailable) {
+
+	  // No.  Wait and try again.
+	  pollTimer.pause();
+	  continue;
+	}
+
+	if (!ReadFile(inputHandle,
+		      bufferPtr,
+		      bufferCapacity,
+		      &nBytesRead,
+		      NULL)) {
+
+	  if (stopReaderFlag) {
+	    break;
+	  }
+
+	  // Broken pipe occurs when the child exits; this is not
+	  // necessarily an error condition.
+	  if (GetLastError() != ERROR_BROKEN_PIPE) {
+
+	    errorText = "Error reading from the child process:  ";
+	    errorText += getErrorText();
+
+	  }
+
+	  break;
+
+	}
+
+      } catch(...) {
+
+	// Some error occurred.
+	if (stopReaderFlag) {
+	  break;
+	}
 
-	// Broken pipe occurs when the child exits; this is not
-	// necessarily an error condition.
+	// Thread was not commanded to stop; output error: Broken pipe
+	// occurs when the child exits; this is not an error
+	// condition.
 	if (GetLastError() != ERROR_BROKEN_PIPE) {
 
 	  errorText = "Error reading from the child process:  ";
@@ -1476,6 +1520,7 @@ namespace CodeDweller {
 
 	}
 
+	// Exit the thread.
 	break;
 
       }