fix(05): WR-01 bound thumb dimensions and decoded image size

lagoon/attach/thumb_test.go

@@ -43,6 +43,28 @@ func TestThumbFilenameRejectsUnsafeTokens(t *testing.T) {
 	}
 }
 
+func TestFileThumbRejectsOutOfRangeSize(t *testing.T) {
+	bucket := memblob.OpenBucket(nil)
+	defer bucket.Close()
+	f := &File{ID: 1, DiskName: "abc123xyz.jpg"}
+	for _, tc := range []struct{ w, h int }{
+		{0, 200},
+		{200, 0},
+		{-1, -1},
+		{maxThumbEdge + 1, 200},
+		{200, maxThumbEdge + 1},
+		{100000, 100000},
+	} {
+		if _, err := f.Thumb(t.Context(), bucket, tc.w, tc.h, "crop"); err == nil {
+			t.Fatalf("size %dx%d must be rejected", tc.w, tc.h)
+		}
+	}
+	iter := bucket.List(nil)
+	if obj, err := iter.Next(t.Context()); err != io.EOF {
+		t.Fatalf("rejected sizes must not touch the bucket, found %v (err %v)", obj, err)
+	}
+}
+
 func TestFileThumbRejectsTraversalMode(t *testing.T) {
 	bucket := memblob.OpenBucket(nil)
 	defer bucket.Close()