cffdump: pager-close

At the end of output, close stdout and hang around until pager process
goes away.  This lets pager realize it is end of input instead of just
trying to wait forever for more output if you try to scroll to the
bottom.

util/cffdump.c

@@ -28,10 +28,12 @@
 #include <unistd.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <sys/wait.h>
 #include <fcntl.h>
 #include <string.h>
 #include <assert.h>
 #include <signal.h>
+#include <errno.h>
 
 #include "redump.h"
 #include "disasm.h"
@@ -1631,6 +1633,24 @@ static void pager_open(void)
 	}
 }
 
+static int pager_close(void)
+{
+	siginfo_t status;
+
+	close(STDOUT_FILENO);
+
+	while (true) {
+		memset(&status, 0, sizeof(status));
+		if (waitid(P_PID, pager_pid, &status, WEXITED) < 0) {
+			if (errno == EINTR)
+				continue;
+			return -errno;
+		}
+
+		return 0;
+	}
+}
+
 int main(int argc, char **argv)
 {
 	int ret, n = 1;
@@ -1762,6 +1782,10 @@ int main(int argc, char **argv)
 
 	script_finish();
 
+	if (interactive) {
+		pager_close();
+	}
+
 	return 0;
 }