Extensions: ensure paths are always included for the "build" command

Scanning the file-system for paths to include didn't detect cases when
explicitly included paths (such as wheels) were missing.

Change the logic to build a list of paths which is merged with pattern
matched paths (de-duplicating), then add all files into the ZIP.
Any missing paths will raise an error.

scripts/addons_core/bl_pkg/cli/blender_ext.py

@@ -2717,13 +2717,19 @@ class subcmd_author:
                 message_error(msg_fn, "Error parsing TOML \"{:s}\" {:s}".format(pkg_manifest_filepath, error_msg))
             return False
 
+        # Always include wheels & manifest.
+        build_paths_extra = (
+            # Inclusion of the manifest is implicit.
+            # No need to require the manifest to include itself.
+            PKG_MANIFEST_FILENAME_TOML,
+            *(manifest.wheels or ()),
+        )
+
         if (manifest_build_data := manifest_data.get("build")) is not None:
-            manifest_build_test = PkgManifest_Build.from_dict_all_errors(manifest_build_data, extra_paths=[
-                # Inclusion of the manifest is implicit.
-                # No need to require the manifest to include itself.
-                PKG_MANIFEST_FILENAME_TOML,
-                *(manifest.wheels or ()),
-            ])
+            manifest_build_test = PkgManifest_Build.from_dict_all_errors(
+                manifest_build_data,
+                extra_paths=build_paths_extra,
+            )
             if isinstance(manifest_build_test, list):
                 for error_msg in manifest_build_test:
                     message_error(msg_fn, "Error parsing TOML \"{:s}\" {:s}".format(pkg_manifest_filepath, error_msg))
@@ -2746,23 +2752,73 @@ class subcmd_author:
         if manifest_build.paths_exclude_pattern is not None:
             build_paths_exclude_pattern = PathPatternMatch(manifest_build.paths_exclude_pattern)
 
-        build_paths: Optional[List[str]] = None
+        build_paths: List[Tuple[str, str]] = []
+
+        # Manifest & wheels.
+        if build_paths_extra:
+            build_paths.extend(build_paths_expand_iter(pkg_source_dir, build_paths_extra))
+
         if manifest_build.paths is not None:
-            build_paths = manifest_build.paths
+            build_paths.extend(build_paths_expand_iter(pkg_source_dir, manifest_build.paths))
+        else:
+            # Mixing literal and pattern matched lists of files is a hassle.
+            # De-duplicate canonical root-relative path names.
+            def filepath_canonical_from_relative(filepath_rel: str):
+                filepath_rel = os.path.normpath(filepath_rel)
+                if os.sep == "\\":
+                    filepath_rel = filepath_rel.replace("\\", "/")
+                return filepath_rel
 
-        def scandir_filter_with_paths_exclude_pattern(filepath: str, is_dir: bool) -> bool:
-            assert build_paths_exclude_pattern is not None
-            if os.sep == "\\":
-                filepath = filepath.replace("\\", "/")
-            if is_dir:
-                assert not filepath.endswith("/")
-                filepath = filepath + "/"
-            assert not filepath.startswith(("/", "./", "../"))
-            return not build_paths_exclude_pattern.test_path(filepath)
+            # Use lowercase to prevent duplicates on MS-Windows.
+            build_paths_extra_canonical: Set[int] = set(
+                filepath_canonical_from_relative(f).lower()
+                for f in build_paths_extra
+            )
 
-        def scandir_filter_fallback(filepath: str, is_dir: bool) -> bool:
-            _ = is_dir
-            return not os.path.basename(filepath).startswith(".")
+            # Scanning the file-system may fail, surround by try/except.
+            try:
+                if build_paths_exclude_pattern:
+                    def scandir_filter_with_paths_exclude_pattern(filepath: str, is_dir: bool) -> bool:
+                        # Returning true includes the file.
+                        assert build_paths_exclude_pattern is not None
+                        if os.sep == "\\":
+                            filepath = filepath.replace("\\", "/")
+                        filepath_canonical = filepath
+                        if is_dir:
+                            assert not filepath.endswith("/")
+                            filepath = filepath + "/"
+                        assert not filepath.startswith(("/", "./", "../"))
+                        result = not build_paths_exclude_pattern.test_path(filepath)
+                        if result and (not is_dir):
+                            # Finally check the path isn't one of the known paths.
+                            if filepath_canonical.lower() in build_paths_extra_canonical:
+                                result = False
+                        return result
+
+                    build_paths.extend(
+                        scandir_recursive(
+                            pkg_source_dir,
+                            filter_fn=scandir_filter_with_paths_exclude_pattern,
+                        ),
+                    )
+                else:
+                    # In this case there isn't really a good option, just ignore all dot-files.
+                    def scandir_filter_fallback(filepath: str, is_dir: bool) -> bool:
+                        # Returning true includes the file.
+                        result = not os.path.basename(filepath).startswith(".")
+                        if result and (not is_dir):
+                            # Finally check the path isn't
+                            if filepath_canonical.lower() in build_paths_extra_canonical:
+                                result = False
+                        return result
+
+                    build_paths.extend(scandir_recursive(pkg_source_dir, filter_fn=scandir_filter_fallback))
+
+                del build_paths_extra_canonical
+
+            except Exception as ex:
+                message_status(msg_fn, "Error building path list \"{:s}\"".format(str(ex)))
+                return False
 
         pkg_filename = manifest.id + PKG_EXT
 
@@ -2797,20 +2853,7 @@ class subcmd_author:
                 return False
 
             with contextlib.closing(zip_fh_context) as zip_fh:
-
-                if build_paths is not None:
-                    filepath_iterator = build_paths_expand_iter(pkg_source_dir, build_paths)
-                else:
-                    filepath_iterator = scandir_recursive(
-                        pkg_source_dir,
-                        filter_fn=(
-                            scandir_filter_with_paths_exclude_pattern if build_paths_exclude_pattern else
-                            # In this case there isn't really a good option, just ignore all dot-files.
-                            scandir_filter_fallback
-                        ),
-                    )
-
-                for filepath_abs, filepath_rel in filepath_iterator:
+                for filepath_abs, filepath_rel in build_paths:
                     if filepath_rel in filenames_root_exclude:
                         continue