Add a new function to the cmdline library to determine whether standard input is connected to a terminal device, and set the --non-interacti…
Add a new function to the cmdline library to determine whether standardinput is connected to a terminal device, and set the --non-interactiveoption if standard input is not connected to a terminal device.The idea is to make 'svn' non-interactive by default if run from scriptswhich are launched in some unattended automated fashion. In such a situationit is possible for scripts to hang if 'svn' decides to prompt for informationsuch as login credentials or conflict resolution options.Also add a new --force-interactive option which enforces the old behaviour.* subversion/include/svn_cmdline.h (svn_cmdline__stdin_isatty): Declare.* subversion/libsvn_subr/cmdline.c: Include io.h on Windows. (svn_cmdline__stdin_isatty): New.* subversion/svn/cl.h (svn_cl__opt_state_t): Add force_interactive option.* subversion/svn/svn.c (svn_cl__longopt_t): Add opt_force_interactive. (sub_main): Set the --non-interactive option based on whether stdin is a tty, unless interactive mode has been forced with --force-interactive. Enforce mutual exclusion of --non-interactive and --force-interactive.* subversion/tests/cmdline/getopt_tests_data/svn_help_log_switch_stdout: Adjust.* subversion/tests/cmdline/update_tests.py (eof_in_interactive_conflict_resolver): Pass --force-interactive to ensure the interactive conflict resolver will be run as expected.