vaxis

fix(vxfw/list): check if index is out of bounds rss

created pr with 95.1 on 2025-12-16T16:06:41Z · by c8ef7d19

added 95.2 on 2025-12-16T16:07:53Z · by c8ef7d19


                      1:  37f44c1 ! 1:  7a2f7ff fix(vxfw/list): check if index is out of bounds

cmds

checkout latest patchset:

ssh pr.pico.sh print 95 | git am -3

checkout any patchset in a patch request:

ssh pr.pico.sh print 95.[rev] | git am -3

add changes to patch request:

git format-patch main --stdout | ssh pr.pico.sh pr add 95

Patchset `95.2` on 2025-12-16T16:07:53Z · commit 7a2f7ff

→ fix(vxfw/list): check if index is out of bounds

Eric Bower 2025-12-16T16:03:32Z

fix(vxfw/list): check if index is out of bounds

Eric Bower 2025-12-16T16:03:32Z

```
panic: runtime error: index out of range [64976] with length 64792

goroutine 53 [running]:
git.sr.ht/~rockorager/vaxis/vxfw.(*Surface).WriteCell(...)
     /go/pkg/mod/git.sr.ht/~rockorager/vaxis@v0.14.1-0.20250527151737-5530f9f4bcf6/vxfw/vxfw.go:158
git.sr.ht/~rockorager/vaxis/vxfw/list.(*Dynamic).Draw(0x40005c9f08, {{0xb?, 0x0?}, {0x0?, 0x0?}, 0x40000309a0?})
     /go/pkg/mod/git.sr.ht/~rockorager/vaxis@v0.14.1-0.20250527151737-5530f9f4bcf6/vxfw/list/list.go:210 +0xca8
```

Semantic diff summary

1 added, 1 modified, 0 signature changed, 0 removed across 2 analyzed files

vxfw/surface_test.go

function_declaration TestWriteCellBoundsCheck added

vxfw/vxfw.go

function_declaration WriteCell modified

+37 -0 vxfw/surface_test.go #

......@@ -0,0 +1,37 @@
package vxfw_test

import (
	"testing"

	"git.sr.ht/~rockorager/vaxis"
	"git.sr.ht/~rockorager/vaxis/vxfw"
)

func TestWriteCellBoundsCheck(t *testing.T) {
	// Create a surface where Size claims more cells than Buffer actually has.
	// This simulates the bug where Size and Buffer get out of sync.
	s := vxfw.Surface{
		Size: vxfw.Size{
			Width:  100,
			Height: 100,
		},
		Buffer: make([]vaxis.Cell, 50), // Only 50 cells, but Size claims 10000
	}

	cell := vaxis.Cell{
		Character: vaxis.Character{
			Grapheme: "x",
			Width:    1,
		},
	}

	// This should not panic even though the index would be out of bounds
	// if we only checked against Size.
	s.WriteCell(99, 99, cell) // Would calculate index 9999, but Buffer only has 50 cells

	// Also test that valid writes still work
	s.WriteCell(0, 0, cell)
	if s.Buffer[0].Character.Grapheme != "x" {
		t.Errorf("expected cell at (0,0) to be written, got %q", s.Buffer[0].Character.Grapheme)
	}
}

+3 -0 vxfw/vxfw.go #

......@@ -155,6 +155,9 @@ func (s *Surface) WriteCell(col uint16, row uint16, cell vaxis.Cell) {
		return
	}
	i := (row * s.Size.Width) + col
	if int(i) >= len(s.Buffer) {
		return
	}
	s.Buffer[i] = cell
}

...	...		@@ -0,0 +1,37 @@
	1	+	package vxfw_test
	2	+
	3	+	import (
	4	+	"testing"
	5	+
	6	+	"git.sr.ht/~rockorager/vaxis"
	7	+	"git.sr.ht/~rockorager/vaxis/vxfw"
	8	+	)
	9	+
	10	+	func TestWriteCellBoundsCheck(t *testing.T) {
	11	+	// Create a surface where Size claims more cells than Buffer actually has.
	12	+	// This simulates the bug where Size and Buffer get out of sync.
	13	+	s := vxfw.Surface{
	14	+	Size: vxfw.Size{
	15	+	Width: 100,
	16	+	Height: 100,
	17	+	},
	18	+	Buffer: make([]vaxis.Cell, 50), // Only 50 cells, but Size claims 10000
	19	+	}
	20	+
	21	+	cell := vaxis.Cell{
	22	+	Character: vaxis.Character{
	23	+	Grapheme: "x",
	24	+	Width: 1,
	25	+	},
	26	+	}
	27	+
	28	+	// This should not panic even though the index would be out of bounds
	29	+	// if we only checked against Size.
	30	+	s.WriteCell(99, 99, cell) // Would calculate index 9999, but Buffer only has 50 cells
	31	+
	32	+	// Also test that valid writes still work
	33	+	s.WriteCell(0, 0, cell)
	34	+	if s.Buffer[0].Character.Grapheme != "x" {
	35	+	t.Errorf("expected cell at (0,0) to be written, got %q", s.Buffer[0].Character.Grapheme)
	36	+	}
	37	+	}

...	...		@@ -155,6 +155,9 @@ func (s *Surface) WriteCell(col uint16, row uint16, cell vaxis.Cell) {
155	155		return
156	156		}
157	157		i := (row * s.Size.Width) + col
	158	+	if int(i) >= len(s.Buffer) {
	159	+	return
	160	+	}
158	161		s.Buffer[i] = cell
159	162		}
160	163

vaxis

Patchset 95.2 on 2025-12-16T16:07:53Z · commit 7a2f7ff

Patchset `95.2` on 2025-12-16T16:07:53Z · commit 7a2f7ff