Implement support for save/restore of DEC private modes (CSI ? s/r)

kitty/data-types.h

@@ -201,22 +201,6 @@ typedef struct {
     DynamicColor configured, overridden;
 } ColorProfile;
 
-#define SAVEPOINTS_SZ 256
-
-typedef struct {
-    uint32_t utf8_state, utf8_codepoint, *g0_charset, *g1_charset, *g_charset;
-    bool use_latin1;
-    Cursor cursor;
-    bool mDECOM, mDECAWM, mDECSCNM;
-
-} Savepoint;
-
-
-typedef struct {
-    Savepoint buf[SAVEPOINTS_SZ];
-    index_type start_of_data, count;
-} SavepointBuffer;
-
 
 #define PARSER_BUF_SZ (8 * 1024)
 #define READ_BUF_SZ (1024*1024)

kitty/parser.c

@@ -370,13 +370,13 @@ screen_cursor_back1(Screen *s, unsigned int count) { screen_cursor_back(s, count
 static inline void
 screen_tabn(Screen *s, unsigned int count) { for (index_type i=0; i < MAX(1, count); i++) screen_tab(s); }
 static inline void
-save_cursor(Screen *s, unsigned int UNUSED param, bool private) {
+save_cursor_or_modes(Screen *s, unsigned int UNUSED param, bool private) {
-    if (private) fprintf(stderr, "%s %s", ERROR_PREFIX, "CSI s in private mode not supported");
+    if (private) screen_save_modes(s);
     else screen_save_cursor(s);
 }
 static inline void
-restore_cursor(Screen *s, unsigned int UNUSED param, bool private) {
+restore_cursor_or_modes(Screen *s, unsigned int UNUSED param, bool private) {
-    if (private) fprintf(stderr, "%s %s", ERROR_PREFIX, "CSI u in private mode not supported");
+    if (private) screen_restore_modes(s);
     else screen_restore_cursor(s);
 }
 
@@ -690,9 +690,9 @@ dispatch_csi(Screen *screen, PyObject DUMP_UNUSED *dump_callback) {
         case DSR:
             CALL_CSI_HANDLER1P(report_device_status, 0, '?');
         case SC:
-            CALL_CSI_HANDLER1P(save_cursor, 0, '?');
+            CALL_CSI_HANDLER1P(save_cursor_or_modes, 0, '?');
         case RC:
-            CALL_CSI_HANDLER1P(restore_cursor, 0, '?');
+            CALL_CSI_HANDLER1P(restore_cursor_or_modes, 0, '?');
         case 'r':
             if (!start_modifier && !end_modifier) {
                 // DECSTBM

kitty/screen.c

@@ -748,19 +748,18 @@ screen_linefeed(Screen *self) {
     screen_ensure_bounds(self, false);
 }
 
-static inline Savepoint*
+#define buffer_push(self, ans) { \
-savepoints_push(SavepointBuffer *self) {
+    ans = (self)->buf + (((self)->start_of_data + (self)->count) % SAVEPOINTS_SZ); \
-    Savepoint *ans = self->buf + ((self->start_of_data + self->count) % SAVEPOINTS_SZ);
+    if ((self)->count == SAVEPOINTS_SZ) (self)->start_of_data = ((self)->start_of_data + 1) % SAVEPOINTS_SZ; \
-    if (self->count == SAVEPOINTS_SZ) self->start_of_data = (self->start_of_data + 1) % SAVEPOINTS_SZ;
+    else (self)->count++; \
-    else self->count++;
-    return ans;
 }
 
-static inline Savepoint*
+#define buffer_pop(self, ans) { \
-savepoints_pop(SavepointBuffer *self) {
+    if ((self)->count == 0) ans = NULL; \
-    if (self->count == 0) return NULL;
+    else { \
-    self->count--;
+        (self)->count--; \
-    return self->buf + ((self->start_of_data + self->count) % SAVEPOINTS_SZ);
+        ans = (self)->buf + (((self)->start_of_data + (self)->count) % SAVEPOINTS_SZ); \
+    } \
 }
 
 #define COPY_CHARSETS(self, sp) \
@@ -774,7 +773,8 @@ savepoints_pop(SavepointBuffer *self) {
 void
 screen_save_cursor(Screen *self) {
     SavepointBuffer *pts = self->linebuf == self->main_linebuf ? &self->main_savepoints : &self->alt_savepoints;
-    Savepoint *sp = savepoints_push(pts);
+    Savepoint *sp;
+    buffer_push(pts, sp);
     cursor_copy_to(self->cursor, &(sp->cursor));
     sp->mDECOM = self->modes.mDECOM;
     sp->mDECAWM = self->modes.mDECAWM;
@@ -782,10 +782,18 @@ screen_save_cursor(Screen *self) {
     COPY_CHARSETS(self, sp);
 }
 
+void
+screen_save_modes(Screen *self) {
+    ScreenModes *m;
+    buffer_push(&self->modes_savepoints, m);
+    *m = self->modes;
+}
+
 void
 screen_restore_cursor(Screen *self) {
     SavepointBuffer *pts = self->linebuf == self->main_linebuf ? &self->main_savepoints : &self->alt_savepoints;
-    Savepoint *sp = savepoints_pop(pts);
+    Savepoint *sp;
+    buffer_pop(pts, sp);
     if (sp == NULL) {
         screen_cursor_position(self, 1, 1);
         screen_reset_mode(self, DECOM);
@@ -801,6 +809,15 @@ screen_restore_cursor(Screen *self) {
     }
 }
 
+void
+screen_restore_modes(Screen *self) {
+    ScreenModes *m;
+    buffer_pop(&self->modes_savepoints, m);
+    bool lnm = self->modes.mLNM, irm = self->modes.mIRM, sc81t = self->modes.eight_bit_controls;
+    self->modes = *m;
+    self->modes.mLNM = lnm; self->modes.mIRM = irm; self->modes.eight_bit_controls = sc81t;
+}
+
 void
 screen_ensure_bounds(Screen *self, bool force_use_margins/*=false*/) {
     unsigned int top, bottom;

kitty/screen.h

@@ -27,6 +27,29 @@ typedef struct {
     bool in_progress;
 } Selection;
 
+#define SAVEPOINTS_SZ 256
+
+typedef struct {
+    uint32_t utf8_state, utf8_codepoint, *g0_charset, *g1_charset, *g_charset;
+    bool use_latin1;
+    Cursor cursor;
+    bool mDECOM, mDECAWM, mDECSCNM;
+
+} Savepoint;
+
+
+typedef struct {
+    Savepoint buf[SAVEPOINTS_SZ];
+    index_type start_of_data, count;
+} SavepointBuffer;
+
+
+typedef struct {
+    ScreenModes buf[SAVEPOINTS_SZ];
+    index_type start_of_data, count;
+} SavemodesBuffer;
+
+
 typedef struct {
     PyObject_HEAD
 
@@ -39,6 +62,7 @@ typedef struct {
     bool use_latin1, selection_updated_once, is_dirty, scroll_changed, rectangle_select;
     Cursor *cursor;
     SavepointBuffer main_savepoints, alt_savepoints;
+    SavemodesBuffer modes_savepoints;
     PyObject *callbacks, *test_child;
     LineBuf *linebuf, *main_linebuf, *alt_linebuf;
     GraphicsManager *grman, *main_grman, *alt_grman;
@@ -67,6 +91,8 @@ void parse_worker_dump(Screen *screen, PyObject *dump_callback);
 void screen_align(Screen*);
 void screen_restore_cursor(Screen *);
 void screen_save_cursor(Screen *);
+void screen_restore_modes(Screen *);
+void screen_save_modes(Screen *);
 void write_escape_code_to_child(Screen *self, unsigned char which, const char *data);
 void screen_cursor_position(Screen*, unsigned int, unsigned int);
 void screen_cursor_back(Screen *self, unsigned int count/*=1*/, int move_direction/*=-1*/);