Zebediah Figura : shell32: Fix parsing empty arguments in parse_dde_command().

[Alexandre Julliard]

Module: wine
Branch: master
Commit: eb06f991725d21e1ce4e3353a377e8708ae8471f
URL:    https://gitlab.winehq.org/wine/wine/-/commit/eb06f991725d21e1ce4e3353a377e87...

Author: Zebediah Figura <zfigura(a)codeweavers.com>
Date:   Mon Oct  9 11:56:43 2023 -0500

shell32: Fix parsing empty arguments in parse_dde_command().

This fixes a hang in Microsoft Visual C++ 1.52 installation.

---

 dlls/shell32/dde.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dlls/shell32/dde.c b/dlls/shell32/dde.c
index dcaf641f8f4..976dc2e394a 100644
--- a/dlls/shell32/dde.c
+++ b/dlls/shell32/dde.c
@@ -391,7 +391,7 @@ static DWORD parse_dde_command(HSZ hszTopic, WCHAR *command)
                 else
                 {
                     if (!(p = wcspbrk(command, L",()[]"))) goto error;
-                    while (p[-1] == ' ') p--;
+                    while (p > command && p[-1] == ' ') p--;
                 }
 
                 new_argv = realloc(argv, (argc + 1) * sizeof(*argv));