plugins_(on|pre) API now maybe returns NULL.

Instead of always returning a `strdup()`'ed version, maybe return NULL and
handle this in the calling code.

This is still not true for `plugins_pre_chat_message_display()`, where we
return the passed `messag` in case there are no plugins, since this would
require a bigger refactor of more parts.

This also
* merges the implementation of `sv_ev_incoming_private_message()` and
  `sv_ev_delayed_private_message()`, since they differed only by a single
  line.
* untangles the `#ifdef` mess in `cl_ev_send_muc_msg_corrected()`.

Signed-off-by: Steffen Jaeckel <s@jaeckel.eu>

src/event/client_events.c

@@ -137,9 +137,7 @@ cl_ev_send_msg_correct(ProfChatWin* chatwin, const char* const msg, const char*
     gboolean request_receipt = prefs_get_boolean(PREF_RECEIPTS_REQUEST);
 
     auto_char char* plugin_msg = plugins_pre_chat_message_send(chatwin->barejid, msg);
-    if (plugin_msg == NULL) {
+    const char* const message = plugin_msg ?: msg;
-        return;
-    }
 
     char* replace_id = NULL;
     if (correct_last_msg) {
@@ -148,46 +146,46 @@ cl_ev_send_msg_correct(ProfChatWin* chatwin, const char* const msg, const char*
 
     if (chatwin->is_omemo) {
 #ifdef HAVE_OMEMO
-        auto_char char* id = omemo_on_message_send((ProfWin*)chatwin, plugin_msg, request_receipt, FALSE, replace_id);
+        auto_char char* id = omemo_on_message_send((ProfWin*)chatwin, message, request_receipt, FALSE, replace_id);
         if (id != NULL) {
-            chat_log_omemo_msg_out(chatwin->barejid, plugin_msg, NULL);
+            chat_log_omemo_msg_out(chatwin->barejid, message, NULL);
-            log_database_add_outgoing_chat(id, chatwin->barejid, plugin_msg, replace_id, PROF_MSG_ENC_OMEMO);
+            log_database_add_outgoing_chat(id, chatwin->barejid, message, replace_id, PROF_MSG_ENC_OMEMO);
-            chatwin_outgoing_msg(chatwin, plugin_msg, id, PROF_MSG_ENC_OMEMO, request_receipt, replace_id);
+            chatwin_outgoing_msg(chatwin, message, id, PROF_MSG_ENC_OMEMO, request_receipt, replace_id);
         }
 #endif
     } else if (chatwin->is_ox) {
 #ifdef HAVE_LIBGPGME
         // XEP-0373: OpenPGP for XMPP
-        auto_char char* id = message_send_chat_ox(chatwin->barejid, plugin_msg, request_receipt, replace_id);
+        auto_char char* id = message_send_chat_ox(chatwin->barejid, message, request_receipt, replace_id);
         if (id != NULL) {
-            chat_log_pgp_msg_out(chatwin->barejid, plugin_msg, NULL);
+            chat_log_pgp_msg_out(chatwin->barejid, message, NULL);
-            log_database_add_outgoing_chat(id, chatwin->barejid, plugin_msg, replace_id, PROF_MSG_ENC_OX);
+            log_database_add_outgoing_chat(id, chatwin->barejid, message, replace_id, PROF_MSG_ENC_OX);
-            chatwin_outgoing_msg(chatwin, plugin_msg, id, PROF_MSG_ENC_OX, request_receipt, replace_id);
+            chatwin_outgoing_msg(chatwin, message, id, PROF_MSG_ENC_OX, request_receipt, replace_id);
         }
 #endif
     } else if (chatwin->pgp_send) {
 #ifdef HAVE_LIBGPGME
-        auto_char char* id = message_send_chat_pgp(chatwin->barejid, plugin_msg, request_receipt, replace_id);
+        auto_char char* id = message_send_chat_pgp(chatwin->barejid, message, request_receipt, replace_id);
         if (id != NULL) {
-            chat_log_pgp_msg_out(chatwin->barejid, plugin_msg, NULL);
+            chat_log_pgp_msg_out(chatwin->barejid, message, NULL);
-            log_database_add_outgoing_chat(id, chatwin->barejid, plugin_msg, replace_id, PROF_MSG_ENC_PGP);
+            log_database_add_outgoing_chat(id, chatwin->barejid, message, replace_id, PROF_MSG_ENC_PGP);
-            chatwin_outgoing_msg(chatwin, plugin_msg, id, PROF_MSG_ENC_PGP, request_receipt, replace_id);
+            chatwin_outgoing_msg(chatwin, message, id, PROF_MSG_ENC_PGP, request_receipt, replace_id);
         }
 #endif
     } else {
         gboolean handled = FALSE;
 #ifdef HAVE_LIBOTR
-        handled = otr_on_message_send(chatwin, plugin_msg, request_receipt, replace_id);
+        handled = otr_on_message_send(chatwin, message, request_receipt, replace_id);
 #endif
         if (!handled) {
-            auto_char char* id = message_send_chat(chatwin->barejid, plugin_msg, oob_url, request_receipt, replace_id);
+            auto_char char* id = message_send_chat(chatwin->barejid, message, oob_url, request_receipt, replace_id);
-            chat_log_msg_out(chatwin->barejid, plugin_msg, NULL);
+            chat_log_msg_out(chatwin->barejid, message, NULL);
-            log_database_add_outgoing_chat(id, chatwin->barejid, plugin_msg, replace_id, PROF_MSG_ENC_NONE);
+            log_database_add_outgoing_chat(id, chatwin->barejid, message, replace_id, PROF_MSG_ENC_NONE);
-            chatwin_outgoing_msg(chatwin, plugin_msg, id, PROF_MSG_ENC_NONE, request_receipt, replace_id);
+            chatwin_outgoing_msg(chatwin, message, id, PROF_MSG_ENC_NONE, request_receipt, replace_id);
         }
     }
 
-    plugins_post_chat_message_send(chatwin->barejid, plugin_msg);
+    plugins_post_chat_message_send(chatwin->barejid, message);
     return;
 }
 
@@ -201,9 +199,7 @@ void
 cl_ev_send_muc_msg_corrected(ProfMucWin* mucwin, const char* const msg, const char* const oob_url, gboolean correct_last_msg)
 {
     auto_char char* plugin_msg = plugins_pre_room_message_send(mucwin->roomjid, msg);
-    if (plugin_msg == NULL) {
+    const char* const message = plugin_msg ?: msg;
-        return;
-    }
 
     char* replace_id = NULL;
     if (correct_last_msg) {
@@ -212,30 +208,21 @@ cl_ev_send_muc_msg_corrected(ProfMucWin* mucwin, const char* const msg, const ch
 
 #ifdef HAVE_OMEMO
     if (mucwin->is_omemo) {
-        auto_char char* id = omemo_on_message_send((ProfWin*)mucwin, plugin_msg, FALSE, TRUE, replace_id);
+        auto_char char* id = omemo_on_message_send((ProfWin*)mucwin, message, FALSE, TRUE, replace_id);
-        groupchat_log_omemo_msg_out(mucwin->roomjid, plugin_msg);
+        groupchat_log_omemo_msg_out(mucwin->roomjid, message);
-        log_database_add_outgoing_muc(id, mucwin->roomjid, plugin_msg, replace_id, PROF_MSG_ENC_OMEMO);
+        log_database_add_outgoing_muc(id, mucwin->roomjid, message, replace_id, PROF_MSG_ENC_OMEMO);
-        mucwin_outgoing_msg(mucwin, plugin_msg, id, PROF_MSG_ENC_OMEMO, replace_id);
+        mucwin_outgoing_msg(mucwin, message, id, PROF_MSG_ENC_OMEMO, replace_id);
-    } else {
+    } else
-        auto_char char* id = message_send_groupchat(mucwin->roomjid, plugin_msg, oob_url, replace_id);
+#endif
-        groupchat_log_msg_out(mucwin->roomjid, plugin_msg);
+    {
-        log_database_add_outgoing_muc(id, mucwin->roomjid, plugin_msg, replace_id, PROF_MSG_ENC_NONE);
+        auto_char char* id = message_send_groupchat(mucwin->roomjid, message, oob_url, replace_id);
-        mucwin_outgoing_msg(mucwin, plugin_msg, id, PROF_MSG_ENC_NONE, replace_id);
+        groupchat_log_msg_out(mucwin->roomjid, message);
+        log_database_add_outgoing_muc(id, mucwin->roomjid, message, replace_id, PROF_MSG_ENC_NONE);
+        mucwin_outgoing_msg(mucwin, message, id, PROF_MSG_ENC_NONE, replace_id);
     }
 
-    plugins_post_room_message_send(mucwin->roomjid, plugin_msg);
+    plugins_post_room_message_send(mucwin->roomjid, message);
     return;
-#endif
-
-#ifndef HAVE_OMEMO
-    auto_char char* id = message_send_groupchat(mucwin->roomjid, plugin_msg, oob_url, replace_id);
-    groupchat_log_msg_out(mucwin->roomjid, plugin_msg);
-    log_database_add_outgoing_muc(id, mucwin->roomjid, plugin_msg, replace_id, PROF_MSG_ENC_NONE);
-    mucwin_outgoing_msg(mucwin, plugin_msg, id, PROF_MSG_ENC_NONE, replace_id);
-
-    plugins_post_room_message_send(mucwin->roomjid, plugin_msg);
-    return;
-#endif
 }
 
 void
@@ -253,13 +240,14 @@ cl_ev_send_priv_msg(ProfPrivateWin* privwin, const char* const msg, const char*
         privwin_message_left_room(privwin);
     } else {
         auto_char char* plugin_msg = plugins_pre_priv_message_send(privwin->fulljid, msg);
+        const char* const message = plugin_msg ?: msg;
         auto_jid Jid* jidp = jid_create(privwin->fulljid);
 
-        auto_char char* id = message_send_private(privwin->fulljid, plugin_msg, oob_url);
+        auto_char char* id = message_send_private(privwin->fulljid, message, oob_url);
-        chat_log_msg_out(jidp->barejid, plugin_msg, jidp->resourcepart);
+        chat_log_msg_out(jidp->barejid, message, jidp->resourcepart);
-        log_database_add_outgoing_muc_pm(id, privwin->fulljid, plugin_msg, NULL, PROF_MSG_ENC_NONE);
+        log_database_add_outgoing_muc_pm(id, privwin->fulljid, message, NULL, PROF_MSG_ENC_NONE);
-        privwin_outgoing_msg(privwin, plugin_msg);
+        privwin_outgoing_msg(privwin, message);
 
-        plugins_post_priv_message_send(privwin->fulljid, plugin_msg);
+        plugins_post_priv_message_send(privwin->fulljid, message);
     }
 }

src/event/server_events.c

@@ -345,7 +345,9 @@ sv_ev_room_message(ProfMessage* message)
     }
 
     char* old_plain = message->plain;
-    message->plain = plugins_pre_room_message_display(message->from_jid->barejid, message->from_jid->resourcepart, message->plain);
+    auto_char char* plugin_msg = plugins_pre_room_message_display(message->from_jid->barejid, message->from_jid->resourcepart, message->plain);
+    if (plugin_msg)
+        message->plain = plugin_msg;
 
     GSList* mentions = get_mentions(prefs_get_boolean(PREF_NOTIFY_MENTION_WHOLE_WORD), prefs_get_boolean(PREF_NOTIFY_MENTION_CASE_SENSITIVE), message->plain, mynick);
     gboolean mention = g_slist_length(mentions) > 0;
@@ -409,55 +411,44 @@ sv_ev_room_message(ProfMessage* message)
     rosterwin_roster();
 
     plugins_post_room_message_display(message->from_jid->barejid, message->from_jid->resourcepart, message->plain);
-    free(message->plain);
+    message->plain = old_plain;
+}
+
+static void
+_sv_ev_private_message(ProfMessage* message)
+{
+    char* old_plain = message->plain;
+    auto_char char* plugin_msg = plugins_pre_priv_message_display(message->from_jid->fulljid, message->plain);
+    if (plugin_msg)
+        message->plain = plugin_msg;
+
+    ProfPrivateWin* privatewin = wins_get_private(message->from_jid->fulljid);
+    if (privatewin == NULL) {
+        ProfWin* window = wins_new_private(message->from_jid->fulljid);
+        privatewin = (ProfPrivateWin*)window;
+    }
+
+    _clean_incoming_message(message);
+    privwin_incoming_msg(privatewin, message);
+    // Intentionally skipping log to DB because we can't authenticate the sender
+    chat_log_msg_in(message);
+
+    plugins_post_priv_message_display(message->from_jid->fulljid, message->plain);
+
     message->plain = old_plain;
 }
 
 void
 sv_ev_incoming_private_message(ProfMessage* message)
 {
-    char* old_plain = message->plain;
+    _sv_ev_private_message(message);
-    message->plain = plugins_pre_priv_message_display(message->from_jid->fulljid, message->plain);
-
-    ProfPrivateWin* privatewin = wins_get_private(message->from_jid->fulljid);
-    if (privatewin == NULL) {
-        ProfWin* window = wins_new_private(message->from_jid->fulljid);
-        privatewin = (ProfPrivateWin*)window;
-    }
-
-    _clean_incoming_message(message);
-    privwin_incoming_msg(privatewin, message);
-    // Intentionally skipping log to DB because we can't authenticate the sender
-    chat_log_msg_in(message);
-
-    plugins_post_priv_message_display(message->from_jid->fulljid, message->plain);
-
-    free(message->plain);
-    message->plain = old_plain;
     rosterwin_roster();
 }
 
 void
 sv_ev_delayed_private_message(ProfMessage* message)
 {
-    char* old_plain = message->plain;
+    _sv_ev_private_message(message);
-    message->plain = plugins_pre_priv_message_display(message->from_jid->fulljid, message->plain);
-
-    ProfPrivateWin* privatewin = wins_get_private(message->from_jid->fulljid);
-    if (privatewin == NULL) {
-        ProfWin* window = wins_new_private(message->from_jid->fulljid);
-        privatewin = (ProfPrivateWin*)window;
-    }
-
-    _clean_incoming_message(message);
-    privwin_incoming_msg(privatewin, message);
-    // Intentionally skipping log to DB because we can't authenticate the sender
-    chat_log_msg_in(message);
-
-    plugins_post_priv_message_display(message->from_jid->fulljid, message->plain);
-
-    free(message->plain);
-    message->plain = old_plain;
 }
 
 void

src/plugins/plugins.c

@@ -517,10 +517,14 @@ plugins_on_disconnect(const char* const account_name, const char* const fulljid)
 char*
 plugins_pre_chat_message_display(const char* const barejid, const char* const resource, char* message)
 {
+    GList* values = g_hash_table_get_values(plugins);
+    if (!values) {
+        return message;
+    }
+
     char* new_message = NULL;
     char* curr_message = message;
 
-    GList* values = g_hash_table_get_values(plugins);
     GList* curr = values;
     while (curr) {
         ProfPlugin* plugin = curr->data;
@@ -552,10 +556,14 @@ plugins_post_chat_message_display(const char* const barejid, const char* const r
 char*
 plugins_pre_chat_message_send(const char* const barejid, const char* message)
 {
+    GList* values = g_hash_table_get_values(plugins);
+    if (!values) {
+        return NULL;
+    }
+
     char* new_message = NULL;
     char* curr_message = strdup(message);
 
-    GList* values = g_hash_table_get_values(plugins);
     GList* curr = values;
     while (curr) {
         ProfPlugin* plugin = curr->data;
@@ -595,10 +603,14 @@ plugins_post_chat_message_send(const char* const barejid, const char* message)
 char*
 plugins_pre_room_message_display(const char* const barejid, const char* const nick, const char* message)
 {
+    GList* values = g_hash_table_get_values(plugins);
+    if (!values) {
+        return NULL;
+    }
+
     char* new_message = NULL;
     char* curr_message = strdup(message);
 
-    GList* values = g_hash_table_get_values(plugins);
     GList* curr = values;
     while (curr) {
         ProfPlugin* plugin = curr->data;
@@ -631,10 +643,14 @@ plugins_post_room_message_display(const char* const barejid, const char* const n
 char*
 plugins_pre_room_message_send(const char* const barejid, const char* message)
 {
+    GList* values = g_hash_table_get_values(plugins);
+    if (!values) {
+        return NULL;
+    }
+
     char* new_message = NULL;
     char* curr_message = strdup(message);
 
-    GList* values = g_hash_table_get_values(plugins);
     GList* curr = values;
     while (curr) {
         ProfPlugin* plugin = curr->data;
@@ -697,11 +713,15 @@ plugins_on_room_history_message(const char* const barejid, const char* const nic
 char*
 plugins_pre_priv_message_display(const char* const fulljid, const char* message)
 {
+    GList* values = g_hash_table_get_values(plugins);
+    if (!values) {
+        return NULL;
+    }
+
     auto_jid Jid* jidp = jid_create(fulljid);
     char* new_message = NULL;
     char* curr_message = strdup(message);
 
-    GList* values = g_hash_table_get_values(plugins);
     GList* curr = values;
     while (curr) {
         ProfPlugin* plugin = curr->data;
@@ -735,11 +755,15 @@ plugins_post_priv_message_display(const char* const fulljid, const char* message
 char*
 plugins_pre_priv_message_send(const char* const fulljid, const char* const message)
 {
+    GList* values = g_hash_table_get_values(plugins);
+    if (!values) {
+        return NULL;
+    }
+
     auto_jid Jid* jidp = jid_create(fulljid);
     char* new_message = NULL;
     char* curr_message = strdup(message);
 
-    GList* values = g_hash_table_get_values(plugins);
     GList* curr = values;
     while (curr) {
         ProfPlugin* plugin = curr->data;
@@ -782,10 +806,14 @@ plugins_post_priv_message_send(const char* const fulljid, const char* const mess
 char*
 plugins_on_message_stanza_send(const char* const text)
 {
+    GList* values = g_hash_table_get_values(plugins);
+    if (!values) {
+        return NULL;
+    }
+
     char* new_stanza = NULL;
     char* curr_stanza = strdup(text);
 
-    GList* values = g_hash_table_get_values(plugins);
     GList* curr = values;
     while (curr) {
         ProfPlugin* plugin = curr->data;
@@ -825,10 +853,14 @@ plugins_on_message_stanza_receive(const char* const text)
 char*
 plugins_on_presence_stanza_send(const char* const text)
 {
+    GList* values = g_hash_table_get_values(plugins);
+    if (!values) {
+        return NULL;
+    }
+
     char* new_stanza = NULL;
     char* curr_stanza = strdup(text);
 
-    GList* values = g_hash_table_get_values(plugins);
     GList* curr = values;
     while (curr) {
         ProfPlugin* plugin = curr->data;
@@ -868,10 +900,14 @@ plugins_on_presence_stanza_receive(const char* const text)
 char*
 plugins_on_iq_stanza_send(const char* const text)
 {
+    GList* values = g_hash_table_get_values(plugins);
+    if (!values) {
+        return NULL;
+    }
+
     char* new_stanza = NULL;
     char* curr_stanza = strdup(text);
 
-    GList* values = g_hash_table_get_values(plugins);
     GList* curr = values;
     while (curr) {
         ProfPlugin* plugin = curr->data;