fmt: prevent rare code corruption with array pre comments (#9908)

cmd/tools/vtest-cleancode.v

@@ -38,7 +38,6 @@ const (
 		'vlib/v/tests/string_interpolation_test.v' /* TODO byteptr: &byte.str() behaves differently than byteptr.str() */,
 		'vlib/v/gen/js/tests/js.v', /* local `hello` fn, gets replaced with module `hello` aliased as `hl` */
 		'examples/c_interop_wkhtmltopdf.v', /* &charptr --> &&char */
-		'examples/path_tracing.v', /* block --> line comments corrupts code */
 		'vlib/v/gen/c/cheaders.v' /* infix wrapping error */,
 	]
 	vfmt_verify_list                = [

vlib/v/fmt/fmt.v

@@ -1428,7 +1428,12 @@ pub fn (mut f Fmt) array_init(node ast.ArrayInit) {
 				f.write(' ')
 			}
 		} else {
-			if c.pos.last_line < node.pos.last_line {
+			next_line := if node.exprs.len > 0 {
+				node.exprs[0].position().line_nr
+			} else {
+				node.pos.last_line
+			}
+			if c.pos.last_line < next_line {
 				f.comment(c, level: .indent)
 				if node.exprs.len == 0 {
 					f.writeln('')

vlib/v/fmt/tests/comments_array_keep.vv

@@ -73,4 +73,7 @@ fn comment_at_line_start_with_expressions_after() {
 	arr := [123456789012345, 234567890123456, 678901234567890, 789012345678901, /* at the end */
 		345678901234567, /* in between */ 456789012345678,
 		/* line start */ 567890123456789, 890123456789012]
+	arr2 := [/* same line pre comment */ Foo{
+		a: 123
+	}]
 }