Merge "RevisionStoreDbTestBase, remove redundant needsDB override"

[lhc/web/wiklou.git] / includes / Storage / SlotRecord.php

diff --git a/includes/Storage/SlotRecord.php b/includes/Storage/SlotRecord.php
index dff4b03..c7eb735 100644 (file)
--- a/includes/Storage/SlotRecord.php
+++ b/includes/Storage/SlotRecord.php
@@ -451,6 +451,16 @@ class SlotRecord {
         * content has been stored in the content table. While building a new revision,
         * SlotRecords will not have an ID associated.
         *
+        * Also, during schema migration, hasContentId() may return false when encountering an
+        * un-migrated database entry in SCHEMA_COMPAT_WRITE_BOTH mode.
+        * It will however always return true for saved revisions on SCHEMA_COMPAT_READ_NEW mode,
+        * or without SCHEMA_COMPAT_WRITE_NEW mode. In the latter case, an emulated content ID
+        * is used, derived from the revision's text ID.
+        *
+        * Note that hasContentId() returning false while hasRevision() returns true always
+        * indicates an unmigrated row in SCHEMA_COMPAT_WRITE_BOTH mode, as described above.
+        * For an unsaved slot, both these methods would return false.
+        *
         * @since 1.32
         *
         * @return bool
@@ -494,6 +504,9 @@ class SlotRecord {
         * This information should be irrelevant to application logic, it is here to allow
         * the construction of a full row for the revision table.
         *
+        * Note that this method may return an emulated value during schema migration in
+        * SCHEMA_COMPAT_WRITE_OLD mode. See RevisionStore::emulateContentId for more information.
+        *
         * @return int
         */
        public function getContentId() {