fix file executable permissions check error on macos in docker container

On macOS Sonoma v14.5, it was discovered that when using avocado in a Docker container
to run scripts without execute permissions, they are considered to have executable permissions.

By directly reading the file's permission bits, the stat method can provide more accurate
permission check results, especially in cases where user context and file system
characteristics might affect the behavior of os.access. This method is closer to the
underlying implementation of the file system, thus providing consistent results across
different environments (such as inside and outside Docker containers). After entering the
container using docker exec -it container bash, use the stat command to check the
file permission bits.

Reference: #5945
Signed-off-by: Kui Li <[email protected]>

avocado/core/resolver.py

@@ -18,6 +18,7 @@
 
 import glob
 import os
+import stat
 from enum import Enum
 
 from avocado.core.enabled_extension_manager import EnabledExtensionManager
@@ -196,11 +197,32 @@ def check_file(
             info=f'File "{path}" does not exist or is not a {type_name}',
         )
 
-    if not os.access(path, access_check):
+    st = os.stat(path)
+
+    user_permissions = st.st_mode & (stat.S_IRUSR | stat.S_IWUSR | stat.S_IXUSR)
+
+    # Initialize required permissions to 0, indicating no permissions are needed yet
+    required_permissions = 0
+
+    # Build the required permissions based on access_check
+    if access_check & os.R_OK:
+        # If read access needs to be checked, set the corresponding user read permission bit
+        required_permissions |= stat.S_IRUSR
+    if access_check & os.W_OK:
+        # If write access needs to be checked, set the corresponding user write permission bit
+        required_permissions |= stat.S_IWUSR
+    if access_check & os.X_OK:
+        # If execute access needs to be checked, set the corresponding user execute permission bit
+        required_permissions |= stat.S_IXUSR
+
+    # Check if the user has the required permissions
+    if (user_permissions & required_permissions) != required_permissions:
+        # If the bitwise AND of user permissions and required permissions is not equal to required permissions,
+        # it means the user is missing some permissions
         return ReferenceResolution(
             reference,
             ReferenceResolutionResult.NOTFOUND,
-            info=f'File "{path}" does not exist or is not {access_name}',
+            info=f'File "{path}" does not have the required {access_name} permissions',
         )
 
     return True