From 6560388f2b9eac7d885e8e89b59c98fb1107a00a Mon Sep 17 00:00:00 2001
From: Yongteng Lei <yongtengrey@outlook.com>
Date: Fri, 12 Dec 2025 12:50:17 +0800
Subject: [PATCH] Fix: correct metadata update behavior (#11919)

### What problem does this PR solve?

Correct metadata update behavior. #11912

When update `value` is omitted, the corresponding keys are updated to
`"value"` regardless of their current values.

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)
---
 api/db/services/document_service.py | 41 ++++++++++++++++++-----------
 1 file changed, 25 insertions(+), 16 deletions(-)

diff --git a/api/db/services/document_service.py b/api/db/services/document_service.py
index 6326ef5de..1f0d8b248 100644
--- a/api/db/services/document_service.py
+++ b/api/db/services/document_service.py
@@ -761,26 +761,35 @@ class DocumentService(CommonService):
                 key = upd.get("key")
                 if not key or key not in meta:
                     continue
+
                 new_value = upd.get("value")
-                match_value = upd.get("match", new_value)
+                match_provided = "match" in upd
                 if isinstance(meta[key], list):
-                    replaced = False
-                    new_list = []
-                    for item in meta[key]:
-                        if match_value and _str_equal(item, match_value):
-                            new_list.append(new_value)
-                            replaced = True
-                        else:
-                            new_list.append(item)
-                    if replaced:
-                        meta[key] = new_list
-                        changed = True
-                else:
-                    if not match_value:
-                        continue
-                    if _str_equal(meta[key], match_value):
+                    if not match_provided:
                         meta[key] = new_value
                         changed = True
+                    else:
+                        match_value = upd.get("match")
+                        replaced = False
+                        new_list = []
+                        for item in meta[key]:
+                            if _str_equal(item, match_value):
+                                new_list.append(new_value)
+                                replaced = True
+                            else:
+                                new_list.append(item)
+                        if replaced:
+                            meta[key] = new_list
+                            changed = True
+                else:
+                    if not match_provided:
+                        meta[key] = new_value
+                        changed = True
+                    else:
+                        match_value = upd.get("match")
+                        if _str_equal(meta[key], match_value):
+                            meta[key] = new_value
+                            changed = True
             return changed
 
         def _apply_deletes(meta):