From 43071528668efbeefebbc34471b3989b782c3c38 Mon Sep 17 00:00:00 2001
From: Huidae Cho <grass4u@gmail.com>
Date: Thu, 7 Dec 2023 08:36:59 -0700
Subject: [PATCH] parser: Support renamed flags (flags/options to options/flags
 as well) (#3256)

* parser: Suppoert renamed flags (flags/options to options/flags as well)

* return after fatal error

* Fix short flag and --overwrite renaming

* Single return for long flag renaming

* Add more specific comments about option value for flag to/from option renaming

* Remove "in GRASS 7"

* Declare and assign renamed_key in one line
---
 lib/gis/parser.c | 87 +++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 83 insertions(+), 4 deletions(-)

diff --git a/lib/gis/parser.c b/lib/gis/parser.c
index c66a82c7aac..d84dcb174f2 100644
--- a/lib/gis/parser.c
+++ b/lib/gis/parser.c
@@ -998,7 +998,8 @@ int module_gui_wx(void)
 void set_flag(int f)
 {
     struct Flag *flag;
-    char *err;
+    char *key, *err;
+    const char *renamed_key;
 
     err = NULL;
 
@@ -1024,6 +1025,67 @@ void set_flag(int f)
         flag = flag->next_flag;
     }
 
+    /* First, check if key has been renamed */
+    G_asprintf(&key, "-%c", f);
+    renamed_key = get_renamed_option(key);
+    G_free(key);
+
+    if (renamed_key) {
+        /* if renamed to a new flag */
+        if (*renamed_key == '-') {
+            /* if renamed to a long flag */
+            if (renamed_key[1] == '-') {
+                if (strcmp(renamed_key, "--overwrite") == 0) {
+                    /* this is a special case for -? to --overwrite */
+                    G_warning(_("Please update the usage of <%s>: "
+                                "flag <%c> has been renamed to <%s>"),
+                              G_program_name(), f, renamed_key);
+                    st->overwrite = 1;
+                }
+                else {
+                    /* long flags other than --overwrite are usually specific to
+                     * GRASS internals, just print an error and let's not
+                     * support them */
+                    G_asprintf(&err,
+                               _("Please update the usage of <%s>: "
+                                 "flag <%c> has been renamed to <%s>"),
+                               G_program_name(), f, renamed_key);
+                    append_error(err);
+                }
+                return;
+            }
+            /* if renamed to a short flag */
+            for (flag = &st->first_flag; flag; flag = flag->next_flag) {
+                if (renamed_key[1] == flag->key) {
+                    G_warning(_("Please update the usage of <%s>: "
+                                "flag <%c> has been renamed to <%s>"),
+                              G_program_name(), f, renamed_key);
+                    flag->answer = 1;
+                    if (flag->suppress_required)
+                        st->suppress_required = 1;
+                    if (flag->suppress_overwrite)
+                        st->suppress_overwrite = 1;
+                    return;
+                }
+            }
+        }
+        else {
+            /* if renamed to a new option (no option value given but will be
+             * required), fatal error */
+            struct Option *opt = NULL;
+            for (opt = &st->first_option; opt; opt = opt->next_opt) {
+                if (strcmp(renamed_key, opt->key) == 0) {
+                    G_asprintf(&err,
+                               _("Please update the usage of <%s>: "
+                                 "flag <%c> has been renamed to option <%s>"),
+                               G_program_name(), f, renamed_key);
+                    append_error(err);
+                    return;
+                }
+            }
+        }
+    }
+
     G_asprintf(&err, _("%s: Sorry, <%c> is not a valid flag"), G_program_name(),
                f);
     append_error(err);
@@ -1175,12 +1237,29 @@ void set_option(const char *string)
     if (found)
         opt = matches[0];
 
-    /* First, check if key has been renamed in GRASS 7 */
+    /* First, check if key has been renamed */
     if (found == 0) {
-        const char *renamed_key = NULL;
+        const char *renamed_key = get_renamed_option(the_key);
 
-        renamed_key = get_renamed_option(the_key);
         if (renamed_key) {
+            /* if renamed to a new flag (option value given but will be lost),
+             * fatal error */
+            if (*renamed_key == '-') {
+                if (renamed_key[1] == '-')
+                    G_asprintf(&err,
+                               _("Please update the usage of <%s>: "
+                                 "option <%s> has been renamed to flag <%s>"),
+                               G_program_name(), the_key, renamed_key);
+                else
+                    G_asprintf(&err,
+                               _("Please update the usage of <%s>: "
+                                 "option <%s> has been renamed to flag <%c>"),
+                               G_program_name(), the_key, renamed_key[1]);
+                append_error(err);
+                return;
+            }
+
+            /* if renamed to a new option */
             for (at_opt = &st->first_option; at_opt;
                  at_opt = at_opt->next_opt) {
                 if (strcmp(renamed_key, at_opt->key) == 0) {