[PATCH v2 0/1] MR10312: vbscript: fix dot member access after line continuation

[Francis De Brabandere (＠francisdb)]

fixes https://bugs.winehq.org/show_bug.cgi?id=56480

The lexer distinguishes '.' (member access) from tDOT (with-statement
expression) by checking the character before the dot. After a line
continuation (_), ptr[-1] is a newline or whitespace instead of the
actual preceding token, causing the dot to be incorrectly treated as
a with-expression.

Track when a line continuation was just consumed and use last_token
to resolve the ambiguity in that case.

--
  v2: vbscript: fix dot member access after line continuation
 
https://gitlab.winehq.org/wine/wine/-/merge_requests/10312

[PATCH v2 1/1] vbscript: fix dot member access after line continuation

[Francis De Brabandere]

From: Francis De Brabandere <[e-mail]>

---
 dlls/vbscript/lex.c          | 10 ++++++++++
 dlls/vbscript/parse.h        |  1 +
 dlls/vbscript/tests/lang.vbs | 15 +++++++++++++++
 3 files changed, 26 insertions(+)

diff --git a/dlls/vbscript/lex.c b/dlls/vbscript/lex.c
index 8c5c69ea429..37a368ce3eb 100644
--- a/dlls/vbscript/lex.c
+++ b/dlls/vbscript/lex.c
@@ -440,6 +440,14 @@ static int parse_next_token(void *lval, unsigned *loc, parser_ctx_t *ctx)
             ctx->ptr++;
             return '.';
         }
+        /* After line continuation, ptr[-1] is a newline or space, but the dot
+         * is logically on the same line as the previous token. */
+        if(ctx->after_continuation
+                && (ctx->last_token == tIdentifier || ctx->last_token == ')'
+                || ctx->last_token == tEMPTYBRACKETS)) {
+            ctx->ptr++;
+            return '.';
+        }
         c = ctx->ptr[1];
         if('0' <= c && c <= '9')
             return parse_numeric_literal(ctx, lval);
@@ -538,6 +546,7 @@ int parser_lex(void *lval, unsigned *loc, parser_ctx_t *ctx)
                 ctx->ptr++;
             if(*ctx->ptr == '\n')
                 ctx->ptr++;
+            ctx->after_continuation = TRUE;
             continue;
         }
         if(ret != tNL || ctx->last_token != tNL)
@@ -546,5 +555,6 @@ int parser_lex(void *lval, unsigned *loc, parser_ctx_t *ctx)
         ctx->last_nl = ctx->ptr-ctx->code;
     }
 
+    ctx->after_continuation = FALSE;
     return (ctx->last_token = ret);
 }
diff --git a/dlls/vbscript/parse.h b/dlls/vbscript/parse.h
index 64c3dee2a69..71fc713ea9c 100644
--- a/dlls/vbscript/parse.h
+++ b/dlls/vbscript/parse.h
@@ -302,6 +302,7 @@ typedef struct {
 
     int last_token;
     unsigned last_nl;
+    BOOL after_continuation;
 
     statement_t *stats;
     statement_t *stats_tail;
diff --git a/dlls/vbscript/tests/lang.vbs b/dlls/vbscript/tests/lang.vbs
index 0025bfeddcf..de91cc21947 100644
--- a/dlls/vbscript/tests/lang.vbs
+++ b/dlls/vbscript/tests/lang.vbs
@@ -247,6 +247,21 @@ x _
 
 x = 3
 
+Class ChainedCallTarget
+    Public Function Ret()
+        Set Ret = Me
+    End Function
+End Class
+
+Dim chainObj
+Set chainObj = New ChainedCallTarget
+chainObj.Ret().Ret()
+chainObj.Ret() _
+.Ret()
+chainObj _
+.Ret() _
+.Ret()
+
 if true then y = true : x = y
 ok x, "x is false"
 
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/10312