[PATCH] Fix missing argument handling in psql getopt

[Quentin Rameau]

When passing an argument option with a missing argument, strcmp would
be called with the argv terminating NULL.
---
 src/bin/psql/startup.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/bin/psql/startup.c b/src/bin/psql/startup.c
index 4730c73396..cffbfc864e 100644
--- a/src/bin/psql/startup.c
+++ b/src/bin/psql/startup.c
@@ -667,12 +667,13 @@ parse_psql_options(int argc, char *argv[], struct 
adhoc_opts *options)
                                break;
                        case '?':
                                /* Actual help option given */
-                               if (strcmp(argv[optind - 1], "-?") == 0)
+                               if (optind <= argc &&
+                                   strcmp(argv[optind - 1], "-?") == 0)
                                {
                                        usage(NOPAGER);
                                        exit(EXIT_SUCCESS);
                                }
-                               /* unknown option reported by getopt */
+                               /* unknown option or missing argument */
                                else
                                        goto unknown_option;
                                break;
-- 
2.23.0