sled

чување 7b8853fd948bff478c6585488e369f7bdad72bc9
родитељ f129b454de2a42b83ee4bbe1a901ec6a695f2a0b
Аутор: Страхиња Радић <contact@strahinja.org>
Датум:   Sat,  8 Jun 2024 15:39:15 +0200

Bugfix: prev_match size_t decrement overflow which lead to segfault

Diffstat:
M
TODO.done
 | 
5
+++--
M
sled.c
 | 
12
+++++++++---

измењених датотека: 2, додавања: 12(+), брисања: 5(-)
diff --git a/TODO.done b/TODO.done
@@ -27,13 +27,14 @@ improperly
 	<change file~ mtime?>	/ only way to appease crontab -e
 	write to file
 
-[/] Investigate segfault:
+[x] Investigate segfault:
 	sled README
 	C-\
 	G
 	/backup
 	N
-    - Can't reproduce it
+	- Can't reproduce it
+	- Fixed 2024-06-08 (size_t decrement bug)
 
 [x] Migrate from using MANDIR to using MANPREFIX like suckless programs
     ex:
diff --git a/sled.c b/sled.c
@@ -1986,12 +1986,15 @@ prev_match(struct DrawState* state)
 	struct BufferLine* current = NULL;
 	const uint32_t* found	   = NULL;
 	size_t idelta;
+	size_t row;
 
 	if (!state->search || !*state->search)
 		return 0;
 
 	*state->error = 0;
-	for (size_t row = state->coord.row; row >= 0; row--)
+	
+	row = state->coord.row;
+	while (row >= 0)
 	{
 		const uint32_t* save_found;
 		current = state->buffer + row;
@@ -2008,7 +2011,7 @@ prev_match(struct DrawState* state)
 		found	   = u32_strrstr(current->text, state->search, found);
 		if (found)
 		{
-			idelta = found - (const uint32_t*)current->text;
+			idelta = found - current->text;
 			state->saved_column
 				= display_length(state, current->text, idelta);
 			if (*current->text)
@@ -2021,7 +2024,10 @@ prev_match(struct DrawState* state)
 			goto prev_match_end;
 		found = save_found - 1;
 		goto prev_match_loop;
-	prev_match_end:;
+	prev_match_end:
+		if (!row)
+			break;
+		row--;
 	}
 	return 0;
 }