Alexandre Julliard : server: Add a helper function for splitting a path into individual elements.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 7b41b7510f5315518fce5dfc5e396fa778b8701a
URL:    https://source.winehq.org/git/wine.git/?a=commit;h=7b41b7510f5315518fce5dfc5e396fa778b8701a

Author: Alexandre Julliard <julliard at winehq.org>
Date:   Tue Mar 24 12:47:31 2020 +0100

server: Add a helper function for splitting a path into individual elements.

Signed-off-by: Alexandre Julliard <julliard at winehq.org>

---

 server/directory.c  | 26 ++++++++++++--------------
 server/object.c     |  9 +++++++++
 server/object.h     |  1 +
 server/winstation.c |  5 ++---
 4 files changed, 24 insertions(+), 17 deletions(-)

diff --git a/server/directory.c b/server/directory.c
index c995487f59..8ee9a97a99 100644
--- a/server/directory.c
+++ b/server/directory.c
@@ -142,30 +142,28 @@ static struct object *directory_lookup_name( struct object *obj, struct unicode_
     struct directory *dir = (struct directory *)obj;
     struct object *found;
     struct unicode_str tmp;
-    const WCHAR *p;
 
     assert( obj->ops == &directory_ops );
 
     if (!name) return NULL;  /* open the directory itself */
 
-    if (!(p = memchrW( name->str, '\\', name->len / sizeof(WCHAR) )))
-        /* Last element in the path name */
-        tmp.len = name->len;
-    else
-        tmp.len = (p - name->str) * sizeof(WCHAR);
-
     tmp.str = name->str;
+    tmp.len = get_path_element( name->str, name->len );
+
     if ((found = find_object( dir->entries, &tmp, attr )))
     {
-        /* Skip trailing \\ */
-        if (p)
+        /* Skip trailing \\ and move to the next element */
+        if (tmp.len < name->len)
         {
-            p++;
             tmp.len += sizeof(WCHAR);
+            name->str += tmp.len / sizeof(WCHAR);
+            name->len -= tmp.len;
+        }
+        else
+        {
+            name->str = NULL;
+            name->len = 0;
         }
-        /* Move to the next element*/
-        name->str = p;
-        name->len -= tmp.len;
         return found;
     }
 
@@ -173,7 +171,7 @@ static struct object *directory_lookup_name( struct object *obj, struct unicode_
     {
         if (tmp.len == 0) /* Double backslash */
             set_error( STATUS_OBJECT_NAME_INVALID );
-        else if (p)  /* Path still has backslashes */
+        else if (tmp.len < name->len)  /* Path still has backslashes */
             set_error( STATUS_OBJECT_PATH_NOT_FOUND );
     }
     return NULL;
diff --git a/server/object.c b/server/object.c
index 94a48c909b..ee89b8698d 100644
--- a/server/object.c
+++ b/server/object.c
@@ -276,6 +276,15 @@ struct object *lookup_named_object( struct object *root, const struct unicode_st
     return parent;
 }
 
+/* return length of first path element in name */
+data_size_t get_path_element( const WCHAR *name, data_size_t len )
+{
+    data_size_t i;
+
+    for (i = 0; i < len / sizeof(WCHAR); i++) if (name[i] == '\\') break;
+    return i * sizeof(WCHAR);
+}
+
 static struct object *create_object( struct object *parent, const struct object_ops *ops,
                                      const struct unicode_str *name, const struct security_descriptor *sd )
 {
diff --git a/server/object.h b/server/object.h
index 4a486e0d63..8114a8fb6b 100644
--- a/server/object.h
+++ b/server/object.h
@@ -135,6 +135,7 @@ extern WCHAR *get_object_full_name( struct object *obj, data_size_t *ret_len );
 extern void dump_object_name( struct object *obj );
 extern struct object *lookup_named_object( struct object *root, const struct unicode_str *name,
                                            unsigned int attr, struct unicode_str *name_left );
+extern data_size_t get_path_element( const WCHAR *name, data_size_t len );
 extern void *create_named_object( struct object *parent, const struct object_ops *ops,
                                   const struct unicode_str *name, unsigned int attributes,
                                   const struct security_descriptor *sd );
diff --git a/server/winstation.c b/server/winstation.c
index b53e367fc1..43d112334d 100644
--- a/server/winstation.c
+++ b/server/winstation.c
@@ -38,7 +38,6 @@
 #include "user.h"
 #include "file.h"
 #include "security.h"
-#include "wine/unicode.h"
 
 
 static struct list winstation_list = LIST_INIT(winstation_list);
@@ -163,7 +162,7 @@ static struct object *winstation_lookup_name( struct object *obj, struct unicode
 
     if (!name) return NULL;  /* open the winstation itself */
 
-    if (memchrW( name->str, '\\', name->len / sizeof(WCHAR) ))  /* no backslash allowed in name */
+    if (get_path_element( name->str, name->len ) < name->len)  /* no backslash allowed in name */
     {
         set_error( STATUS_OBJECT_PATH_SYNTAX_BAD );
         return NULL;
@@ -262,7 +261,7 @@ static int desktop_link_name( struct object *obj, struct object_name *name, stru
         set_error( STATUS_OBJECT_TYPE_MISMATCH );
         return 0;
     }
-    if (memchrW( name->name, '\\', name->len / sizeof(WCHAR) ))  /* no backslash allowed in name */
+    if (get_path_element( name->name, name->len ) < name->len)  /* no backslash allowed in name */
     {
         set_error( STATUS_OBJECT_PATH_SYNTAX_BAD );
         return 0;