Error handling in libjpeg

I am using the C++ JPEG library (libjpeg) and I have realized that when some functions fail exit() is called and the application is closed. How can I override this behavior and prevent the application from closing on libjpeg errors?

This is the default behavior of libjpeg. In order to handle errors with libjpeg, you'll have to define an error handling routine like this:

struct jpegErrorManager {
    /* "public" fields */
    struct jpeg_error_mgr pub;
    /* for return to caller */
    jmp_buf setjmp_buffer;
};
char jpegLastErrorMsg[JMSG_LENGTH_MAX];
void jpegErrorExit (j_common_ptr cinfo)
{
    /* cinfo->err actually points to a jpegErrorManager struct */
    jpegErrorManager* myerr = (jpegErrorManager*) cinfo->err;
    /* note : *(cinfo->err) is now equivalent to myerr->pub */

    /* output_message is a method to print an error message */
    /*(* (cinfo->err->output_message) ) (cinfo);*/      
    
    /* Create the message */
    ( *(cinfo->err->format_message) ) (cinfo, jpegLastErrorMsg);

    /* Jump to the setjmp point */
    longjmp(myerr->setjmp_buffer, 1);
  
}

And then register it using jpeg_std_error.

FILE* fileHandler;
/* ... */
struct jpeg_decompress_struct cinfo;
jpegErrorManager jerr;
cinfo.err = jpeg_std_error(&jerr.pub);
jerr.pub.error_exit = jpegErrorExit;
/* Establish the setjmp return context for my_error_exit to use. */
if (setjmp(jerr.setjmp_buffer)) {
    /* If we get here, the JPEG code has signaled an error. */
    cerr << jpegLastErrorMsg << endl;
    jpeg_destroy_decompress(&cinfo);
    fclose(fileHandler);
    return 1;
}

You can find a complete example here.