cmd: Add a helper function to check if a path ends with a backslash.

programs/cmd/builtins.c

@@ -798,12 +798,12 @@ void WCMD_copy(WCHAR * args) {
 
     /* If parameter is a directory, ensure it ends in \ */
     attributes = GetFileAttributesW(destname);
-    if ((destname[strlenW(destname) - 1] == '\\') ||
+    if (ends_with_backslash( destname ) ||
         ((attributes != INVALID_FILE_ATTRIBUTES) &&
          (attributes & FILE_ATTRIBUTE_DIRECTORY))) {
 
       destisdirectory = TRUE;
-      if (!(destname[strlenW(destname) - 1] == '\\')) strcatW(destname, slashW);
+      if (!ends_with_backslash( destname )) strcatW(destname, slashW);
       WINE_TRACE("Directory, so full name is now '%s'\n", wine_dbgstr_w(destname));
     }
   }
@@ -880,7 +880,7 @@ void WCMD_copy(WCHAR * args) {
 
     /* If parameter is a directory, ensure it ends in \* */
     attributes = GetFileAttributesW(srcpath);
-    if (srcpath[strlenW(srcpath) - 1] == '\\') {
+    if (ends_with_backslash( srcpath )) {
 
       /* We need to know where the filename part starts, so append * and
          recalculate the full resulting path                              */

programs/cmd/directory.c

@@ -833,13 +833,8 @@ void WCMD_directory (WCHAR *args)
       if ((strchrW(path, '*') == NULL) && (strchrW(path, '%') == NULL)) {
         status = GetFileAttributesW(path);
         if ((status != INVALID_FILE_ATTRIBUTES) && (status & FILE_ATTRIBUTE_DIRECTORY)) {
-          if (path[strlenW(path)-1] == '\\') {
-            strcatW (path, starW);
-          }
-          else {
-            static const WCHAR slashStarW[]  = {'\\','*','\0'};
-            strcatW (path, slashStarW);
-          }
+          if (!ends_with_backslash( path )) strcatW( path, slashW );
+          strcatW (path, starW);
         }
       } else {
         /* Special case wildcard search with no extension (ie parameters ending in '.') as

programs/cmd/wcmd.h

@@ -148,6 +148,11 @@ static inline WCHAR *heap_strdupW(const WCHAR *str)
     return ret;
 }
 
+static inline BOOL ends_with_backslash( const WCHAR *path )
+{
+    return path[0] && path[strlenW(path) - 1] == '\\';
+}
+
 /* Data structure to hold context when executing batch files */
 
 typedef struct _BATCH_CONTEXT {