ledit

commit 81ddea61d765938b662b3456b3fe80369cfbc138
parent 626c8692fa7f3dadb3c83a7c5b68b129e9e04ad5
Author: lumidify <nobody@lumidify.org>
Date:   Fri,  6 Oct 2023 11:05:17 +0200

Fix bug with undo

Sometimes, the text would get scrambled when using undo. This was
actually due to a bug in the deletion function that only became
apparent when using undo.

Diffstat:
M
buffer.c
 | 
8
+++++++-
M
undo.c
 | 
32
+++++++++++++++++++++-----------

2 files changed, 28 insertions(+), 12 deletions(-)
diff --git a/buffer.c b/buffer.c
@@ -909,8 +909,12 @@ buffer_prev_char_pos(
 		*byte_ret = cur_byte;
 }
 
+/* The check for length == 0 in buffer_delete_line_section_base and the check for
+   empty range in delete_range_base shouldn't be needed, but I added them just in case. */
 static void
 buffer_delete_line_section_base(ledit_buffer *buffer, size_t line, size_t start, size_t length) {
+	if (length == 0)
+		return;
 	ledit_line *l = buffer_get_line(buffer, line);
 	/* FIXME: somehow make sure this doesn't get optimized out? */
 	(void)add_sz(start, length); /* just check that no overflow */
@@ -928,7 +932,7 @@ buffer_delete_line_section_base(ledit_buffer *buffer, size_t line, size_t start,
 		memmove(
 		    l->text + l->gap,
 		    l->text + l->gap + l->cap - l->len,
-		    start - l->gap
+		    start - l->gap - l->cap + l->len
 		);
 	}
 	l->len -= length;
@@ -947,6 +951,8 @@ delete_range_base(
     size_t line_index1, size_t byte_index1,
     size_t line_index2, size_t byte_index2,
     txtbuf *text_ret) {
+	if (line_index1 == line_index2 && byte_index1 == byte_index2)
+		return;
 	sort_range(&line_index1, &byte_index1, &line_index2, &byte_index2);
 	if (line_index1 == line_index2) {
 		if (text_ret) {
diff --git a/undo.c b/undo.c
@@ -101,6 +101,23 @@ undo_change_mode_group(undo_stack *undo) {
 	undo->change_mode_group = 1;
 }
 
+/*
+static void
+dump_undo(undo_stack *undo) {
+	printf("START UNDO STACK\n");
+	printf("cur: %zu\n", undo->cur);
+	for (size_t i = 0; i < undo->len; i++) {
+		undo_elem *e = &undo->stack[i];
+		printf(
+		    "type %d, mode %d, group %d, mode_group %d, text '%.*s', range (%zu, %zu)\n",
+		    e->type, e->mode, e->group, e->mode_group, (int)e->text->len, e->text->text,
+		    e->op_range.byte1, e->op_range.byte2
+		);
+	}
+	printf("END UNDO STACK\n");
+}
+*/
+
 static void
 push_undo(
     undo_stack *undo, txtbuf *text,
@@ -123,17 +140,7 @@ push_undo(
 		txtbuf_copy(e->text, text);
 	else
 		e->text = txtbuf_dup(text);
-	/*
-	printf("START UNDO STACK\n");
-	for (size_t i = 0; i < undo->len; i++) {
-		undo_elem *e = &undo->stack[i];
-		printf(
-		    "type %d, mode %d, group %d, mode_group %d, text '%.*s'\n",
-		    e->type, e->mode, e->group, e->mode_group, (int)e->text->len, e->text->text
-		);
-	}
-	printf("END UNDO STACK\n");
-	*/
+	/* dump_undo(undo); */
 }
 
 void
@@ -195,6 +202,7 @@ ledit_undo(undo_stack *undo, ledit_mode mode, void *callback_data,
 		switch (e->type) {
 		case UNDO_INSERT:
 			/* FIXME: should the paste buffer also be modified? */
+			/* printf("delete %zu,%zu; %zu,%zu\n", e->op_range.line1, e->op_range.byte1, e->op_range.line2, e->op_range.byte2); */
 			delete_cb(
 			    callback_data,
 			    e->op_range.line1, e->op_range.byte1,
@@ -202,6 +210,7 @@ ledit_undo(undo_stack *undo, ledit_mode mode, void *callback_data,
 			);
 			break;
 		case UNDO_DELETE:
+			/* printf("delete %zu,%zu; %zu,%zu\n", e->op_range.line1, e->op_range.byte1, e->op_range.line2, e->op_range.byte2); */
 			insert_cb(
 			    callback_data,
 			    e->op_range.line1, e->op_range.byte1,
@@ -234,6 +243,7 @@ ledit_undo(undo_stack *undo, ledit_mode mode, void *callback_data,
 	*min_line_ret = min_line;
 	if (mode == NORMAL || mode == VISUAL)
 		undo_change_mode_group(undo);
+	/* dump_undo(undo); */
 	return UNDO_NORMAL;
 }