Fix(Hydrator): disabling identity map now disables the identity map

[xavierleune]

Q	A
Bug fix?	yes
New feature?	no
BC breaks?	no
Deprecations?	no
Tests pass?	yes
Licence	Apache-2.0
Fixed tickets	N/A

Noticed today with a big batch of reads, when trying to optimize the memory consumption, that the identity map was not properly disabled. This PR fixes that.

[vgreb]

Wow ! Good Catch ! Does this bug exists since IdentityMap was introduced ?

[xavierleune]

maybe I should give second thoughts on this one. This change seems really needed but I should probably check there is no unintended side effects more carefully. Seems to be there for a while now, really don't think it's on purpose but these lines makes me doubt: https://github.com/ccmbenchmark/ting/pull/131/changes#diff-1a1e1cbffbe64904034ef60574a22c8b697439bdb644371209c4c7c2a21c5093L337-L339

if (isset($this->references[$ref]) === true) {

      // This entity was already created and stored into references
      if ($this->identityMap === false) {
          // If identityMap is disabled, it clones the object and reset UUID
          $result[$column['table']] = clone $this->references[$ref];
      } else {
        // (...)
      }
     // (...)
}

[xavierleune]

⏺ Here is the full story

Comparison:

• Before (commit bcff473): if ($this->identityMap === true && is_int($table) === false)
• After (commit 8a48050): if (is_int($table) === false)

Date	Commit	Action
Sept 2019	162f539	Bug introduced - references always stored
Aug 2020	bcff473	Fix - added if ($this->identityMap === true) before storage
Aug 2020	8a48050	Revert that reintroduced the bug - condition removed
Dec 2025	dc4de29	Final fix - added && $this->identityMap

What was happening

Even with identityMap disabled:

1. Storage: Entities were always stored in $this->references
2. Retrieval: During rehydration, the code checked $this->identityMap and cloned the object if disabled

So the behavior appeared correct on the surface (objects were cloned), but memory was still being consumed by storing all references. This fix now prevents storage when identityMap is disabled.

[vgreb]

Got it ! Thank you for this fix.