1 files changed, 25 insertions, 16 deletions

diff --git a/txt.c b/txt.c
index 3107b94..a7bf447 100644
--- a/txt.c
+++ b/txt.c
@@ -127,7 +127,7 @@ loop:
 		goto loop;
 	}
 	ASSERT(txt_valid_loc(l));
-	l.t->dirty = 1;
+	l.t->ptbl.dirty = 1;
 	return resolve_loc(l);
 }
 
@@ -237,6 +237,14 @@ void txt_load_empty(Txt *b) {
 	txt_insert_piece(b, 0, TXT_ADD, 0, b->len);
 }
 
+static inline int txt_hist_unchanged(Txt *t) {
+	if (t->hist.n < 1) return 0;
+	TxtPieceTbl *pt = &t->hist.v[t->hist.i];
+	if (t->ptbl.n != pt->n) return 0;
+	if (memcmp(pt->v, t->ptbl.v, sizeof(TxtPiece) * pt->n)) return 0;
+	return 1;
+}
+
 int txt_save(Txt *t, const char *path) {
 	FILE *f = fopen(path, "wb");
 	if (!f) return -1;
@@ -247,7 +255,9 @@ int txt_save(Txt *t, const char *path) {
 	}
 	int e = ferror(f);
 	fclose(f);
-	t->dirty = 0;
+	t->ptbl.dirty = 0;
+	for (u32 i = 0; i < t->hist.n; i++) t->hist.v[i].dirty = 1;
+	if (txt_hist_unchanged(t)) t->hist.v[t->hist.i].dirty = 0;
 	return e ? -1 : 0;
 }
 
@@ -259,12 +269,9 @@ void txt_free(Txt *t) {
 }
 
 void txt_hist_push(Txt *t, TxtLoc cur) {
-	if (t->hist.n > 0) {
-		TxtPieceTbl *pt = &t->hist.v[t->hist.i];
-		if (t->ptbl.n == pt->n && !memcmp(pt->v, t->ptbl.v, sizeof(TxtPiece) * pt->n)) {
-			t->hist.cur[t->hist.i] = cur;
-			return;
-		}
+	if (txt_hist_unchanged(t)) {
+		t->hist.cur[t->hist.i] = cur;
+		return;
 	}
 	if (t->hist.i + 1 < t->hist.n) t->hist.n = t->hist.i + 1;
 	if (t->hist.n == TXT_HIST_MAX) {
@@ -277,28 +284,30 @@ void txt_hist_push(Txt *t, TxtLoc cur) {
 	DA_FIT(&t->hist.v[t->hist.i], t->ptbl.n);
 	memcpy(t->hist.v[t->hist.i].v, t->ptbl.v, sizeof(TxtPiece) * t->ptbl.n);
 	t->hist.v[t->hist.i].n = t->ptbl.n;
+	t->hist.v[t->hist.i].dirty = t->ptbl.dirty;
 	t->hist.cur[t->hist.i] = cur;
 	t->hist.n++;
 }
 
-int txt_hist_fwd(Txt *t, TxtLoc *cur) {
-	if (t->hist.i + 1 >= t->hist.n) return 0;
-	t->hist.i++;
+int txt_hist_set(Txt *t, TxtLoc *cur) {
 	t->ptbl.n = t->hist.v[t->hist.i].n;
 	DA_FIT(&t->ptbl, t->ptbl.n);
 	memcpy(t->ptbl.v, t->hist.v[t->hist.i].v, sizeof(TxtPiece) * t->ptbl.n);
+	t->ptbl.dirty = t->hist.v[t->hist.i].dirty;
 	*cur = t->hist.cur[t->hist.i];
 	return 1;
 }
 
+int txt_hist_fwd(Txt *t, TxtLoc *cur) {
+	if (t->hist.i + 1 >= t->hist.n) return 0;
+	t->hist.i++;
+	return txt_hist_set(t, cur);
+}
+
 int txt_hist_back(Txt *t, TxtLoc *cur) {
 	if (t->hist.i == 0) return 0;
 	t->hist.i--;
-	t->ptbl.n = t->hist.v[t->hist.i].n;
-	DA_FIT(&t->ptbl, t->ptbl.n);
-	memcpy(t->ptbl.v, t->hist.v[t->hist.i].v, sizeof(TxtPiece) * t->ptbl.n);
-	*cur = t->hist.cur[t->hist.i];
-	return 1;
+	return txt_hist_set(t, cur);
 }
 
 Str txt_collect_range(TxtLoc lo, TxtLoc hi, Arena *a) {