Hi Jay
I'm assuming current_char is defined as int?
The 0 is the value returned by parseInt() when it trys to parse a number from the CR and or LF that you are sending after the second valid integer. It waits for a period defined by the serial timeout (default 1s) and then decides that the end of line character(s) are not a number, and returns 0.
If you will be sending the data to the Arduino from the IDE serial monitor, you can set "no line ending" at the bottom right of the window. You may want to reduce the timeout by using Serial.setTimeout() so that the second valid integer is recognised more quickly after you send the string.
Regards
Ray