Commit cc2b17d462 removed the '&&' used to check whether the p4 info command succeeded. This caused incorrect invocation of the p4 diff command.
Add back the check for p4 info command success.
Prior to this commit the command invoked was:
p4 info >/dev/null 2>&1 env P4DIFF= P4COLORS= p4 diff -du0
This commit makes the invocation as:
p4 info >/dev/null 2>&1 && env P4DIFF= P4COLORS= p4 diff -du0