Modifying documents returned by `search` modifies the query cache

[msiemens]

Discussed in #515

^{Originally posted by sakam0to February 23, 2023}
A snippt codes

from tinydb import TinyDB, Query
db =  TinyDB("test.json")
db.insert({"id": 1})

q = Query()
records = db.search(q.id == 1)
records[0]["name"] = "N1"

db.search(q.id==1)
>>[{'id': 1, 'name': 'N1'}]
db.all()
>>[{'id': 1}]

You can see that modifications to the search function result affect the later search results. But it doesn't change the records on the disk. Is it expected or not?

[ShubhamKaudewar]

We need to remove the cache read until we find a solution. Reading from db is ok than wrong data read from cache after modified.

[highyield]

This behaviour can be fixed by returning a deepcopy at line 282 in table.py:

return deepcopy(docs)

Not sure if this is the right approach though, since deepdopy is quite slow