--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -2070,6 +2070,24 @@ next_line_from_context(cctx_T *cctx)
 }
 
 /*
+ * If "*arg" is at the end of the line, advance to the next line.
+ * Return FAIL if beyond the last line, "*arg" is unmodified then.
+ */
+    static int
+may_get_next_line(char_u **arg, cctx_T *cctx)
+{
+    if (**arg == NUL)
+    {
+	char_u *next = next_line_from_context(cctx);
+
+	if (next == NULL)
+	    return FAIL;
+	*arg = skipwhite(next);
+    }
+    return OK;
+}
+
+/*
  * Generate an instruction to load script-local variable "name", without the
  * leading "s:".
  * Also finds imported variables.
@@ -3394,14 +3412,17 @@ compile_expr6(char_u **arg, cctx_T *cctx
 	op = skipwhite(*arg);
 	if (*op != '*' && *op != '/' && *op != '%')
 	    break;
-	if (!VIM_ISWHITE(**arg) || !VIM_ISWHITE(op[1]))
+	if (!IS_WHITE_OR_NUL(**arg) || !IS_WHITE_OR_NUL(op[1]))
 	{
 	    char_u buf[3];
 
 	    vim_strncpy(buf, op, 1);
 	    semsg(_(e_white_both), buf);
+	    return FAIL;
 	}
 	*arg = skipwhite(op + 1);
+	if (may_get_next_line(arg, cctx) == FAIL)
+	    return FAIL;
 
 	// get the second variable
 	if (compile_expr7(arg, cctx) == FAIL)
@@ -3438,15 +3459,18 @@ compile_expr5(char_u **arg, cctx_T *cctx
 	    break;
 	oplen = (*op == '.' ? 2 : 1);
 
-	if (!VIM_ISWHITE(**arg) || !VIM_ISWHITE(op[oplen]))
+	if (!IS_WHITE_OR_NUL(**arg) || !IS_WHITE_OR_NUL(op[oplen]))
 	{
 	    char_u buf[3];
 
 	    vim_strncpy(buf, op, oplen);
 	    semsg(_(e_white_both), buf);
+	    return FAIL;
 	}
 
 	*arg = skipwhite(op + oplen);
+	if (may_get_next_line(arg, cctx) == FAIL)
+	    return FAIL;
 
 	// get the second variable
 	if (compile_expr6(arg, cctx) == FAIL)
@@ -3572,16 +3596,20 @@ compile_expr4(char_u **arg, cctx_T *cctx
 	    ++len;
 	// nothing appended: match case
 
-	if (!VIM_ISWHITE(**arg) || !VIM_ISWHITE(p[len]))
+	if (!IS_WHITE_OR_NUL(**arg) || !IS_WHITE_OR_NUL(p[len]))
 	{
 	    char_u buf[7];
 
 	    vim_strncpy(buf, p, len);
 	    semsg(_(e_white_both), buf);
+	    return FAIL;
 	}
 
 	// get the second variable
 	*arg = skipwhite(p + len);
+	if (may_get_next_line(arg, cctx) == FAIL)
+	    return FAIL;
+
 	if (compile_expr5(arg, cctx) == FAIL)
 	    return FAIL;
 
@@ -3611,8 +3639,11 @@ compile_and_or(char_u **arg, cctx_T *cct
 	ga_init2(&end_ga, sizeof(int), 10);
 	while (p[0] == opchar && p[1] == opchar)
 	{
-	    if (!VIM_ISWHITE(**arg) || !VIM_ISWHITE(p[2]))
+	    if (!IS_WHITE_OR_NUL(**arg) || !IS_WHITE_OR_NUL(p[2]))
+	    {
 		semsg(_(e_white_both), op);
+		return FAIL;
+	    }
 
 	    if (ga_grow(&end_ga, 1) == FAIL)
 	    {
@@ -3626,6 +3657,9 @@ compile_and_or(char_u **arg, cctx_T *cct
 
 	    // eval the next expression
 	    *arg = skipwhite(p + 2);
+	    if (may_get_next_line(arg, cctx) == FAIL)
+		return FAIL;
+
 	    if ((opchar == '|' ? compile_expr3(arg, cctx)
 					   : compile_expr4(arg, cctx)) == FAIL)
 	    {
@@ -3726,13 +3760,19 @@ compile_expr1(char_u **arg,  cctx_T *cct
 	type_T		*type1;
 	type_T		*type2;
 
-	if (!VIM_ISWHITE(**arg) || !VIM_ISWHITE(p[1]))
+	if (!IS_WHITE_OR_NUL(**arg) || !IS_WHITE_OR_NUL(p[1]))
+	{
 	    semsg(_(e_white_both), "?");
+	    return FAIL;
+	}
 
 	generate_JUMP(cctx, JUMP_IF_FALSE, 0);
 
 	// evaluate the second expression; any type is accepted
 	*arg = skipwhite(p + 1);
+	if (may_get_next_line(arg, cctx) == FAIL)
+	    return FAIL;
+
 	if (compile_expr1(arg, cctx) == FAIL)
 	    return FAIL;
 
@@ -3754,11 +3794,17 @@ compile_expr1(char_u **arg,  cctx_T *cct
 	    emsg(_(e_missing_colon));
 	    return FAIL;
 	}
-	if (!VIM_ISWHITE(**arg) || !VIM_ISWHITE(p[1]))
+	if (!IS_WHITE_OR_NUL(**arg) || !IS_WHITE_OR_NUL(p[1]))
+	{
 	    semsg(_(e_white_both), ":");
+	    return FAIL;
+	}
 
 	// evaluate the third expression
 	*arg = skipwhite(p + 1);
+	if (may_get_next_line(arg, cctx) == FAIL)
+	    return FAIL;
+
 	if (compile_expr1(arg, cctx) == FAIL)
 	    return FAIL;