commit 2ffd35fe8fade8f08eadf6b41b40e55b155424b8
author Hirohito Higashi <h.east.727@gmail.com> Tue Jul 08 21:47:01 2025 +0200
committer Christian Brabandt <cb@256bit.org> Tue Jul 08 21:49:56 2025 +0200
tree 8ce9e4e07cc6cb641cbe2179540aa1d8e846a326
parent 32a1b26ef3e821de9b5c518829b08002e933fa5a

patch 9.1.1527: Vim9: Crash with string compound assignment

Problem:  Vim9: Crash when using string compound assignment with wrong
          data type (lacygoill)
Solution: verify expected member type (Hirohito Higashi)

fixes: #17675
closes: #17693

Signed-off-by: Hirohito Higashi <h.east.727@gmail.com>
Signed-off-by: Yegappan Lakshmanan <yegappan@yahoo.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

src/vim9compile.c

diff --git a/src/vim9compile.c b/src/vim9compile.c
index b3cf86c..131bab7 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -3444,7 +3444,13 @@
 
     if (*cac->cac_op == '.')
     {
-	if (may_generate_2STRING(-1, TOSTRING_NONE, cctx) == FAIL)
+	expected = lhs->lhs_member_type;
+	stacktype = get_type_on_stack(cctx, 0);
+	if (expected != &t_string
+		&& need_type(stacktype, expected, FALSE, -1, 0, cctx,
+					FALSE, FALSE) == FAIL)
+	    return FAIL;
+	else if (may_generate_2STRING(-1, TOSTRING_NONE, cctx) == FAIL)
 	    return FAIL;
     }
     else