From a02c0c8d4de96832f2bb3e8c16b8e6e4cf6a9662 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Ekl=C3=B6f?= <daniel@ekloef.se>
Date: Tue, 18 Mar 2025 18:28:09 +0100
Subject: [PATCH] vt: utf8: insert a REPLACEMENT CHARACTER when an invalid
 UTF-8 sequence is detected

---
 vt.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/vt.c b/vt.c
index 173b59a6..1d8297be 100644
--- a/vt.c
+++ b/vt.c
@@ -1041,7 +1041,7 @@ state_utf8_21_switch(struct terminal *term, uint8_t data)
     switch (data) {
         /*              exit                             current                          enter                            new state */
     case 0x80 ... 0xbf:                                  action_utf8_22(term, data);                                       return STATE_GROUND;
-    default: return state_ground_switch(term, data);
+    default:            action_utf8_print(term, 0xfffd); return state_ground_switch(term, data);
     }
 }
 
@@ -1051,7 +1051,7 @@ state_utf8_31_switch(struct terminal *term, uint8_t data)
     switch (data) {
         /*              exit                             current                          enter                            new state */
     case 0x80 ... 0xbf:                                  action_utf8_32(term, data);                                       return STATE_UTF8_32;
-    default: return state_ground_switch(term, data);
+    default:            action_utf8_print(term, 0xfffd); return state_ground_switch(term, data);
     }
 }
 
@@ -1061,7 +1061,7 @@ state_utf8_32_switch(struct terminal *term, uint8_t data)
     switch (data) {
         /*              exit                             current                          enter                            new state */
     case 0x80 ... 0xbf:                                  action_utf8_33(term, data);                                       return STATE_GROUND;
-    default: return state_ground_switch(term, data);
+    default:            action_utf8_print(term, 0xfffd); return state_ground_switch(term, data);
     }
 }
 
@@ -1071,7 +1071,7 @@ state_utf8_41_switch(struct terminal *term, uint8_t data)
     switch (data) {
         /*              exit                             current                          enter                            new state */
     case 0x80 ... 0xbf:                                  action_utf8_42(term, data);                                       return STATE_UTF8_42;
-    default: return state_ground_switch(term, data);
+    default:            action_utf8_print(term, 0xfffd); return state_ground_switch(term, data);
     }
 }
 
@@ -1081,7 +1081,7 @@ state_utf8_42_switch(struct terminal *term, uint8_t data)
     switch (data) {
         /*              exit                             current                          enter                            new state */
     case 0x80 ... 0xbf:                                  action_utf8_43(term, data);                                       return STATE_UTF8_43;
-    default: return state_ground_switch(term, data);
+    default:            action_utf8_print(term, 0xfffd); return state_ground_switch(term, data);
     }
 }
 
@@ -1091,7 +1091,7 @@ state_utf8_43_switch(struct terminal *term, uint8_t data)
     switch (data) {
         /*              exit                             current                          enter                            new state */
     case 0x80 ... 0xbf:                                  action_utf8_44(term, data);                                       return STATE_GROUND;
-    default: return state_ground_switch(term, data);
+    default:            action_utf8_print(term, 0xfffd); return state_ground_switch(term, data);
     }
 }