`ToolsFunctionOutput::__construct()` leaves `$name` uninitialized when input function is NULL, causing a PHP fatal (#3583760) · Issues · project / ai

`ToolsFunctionOutput::__construct()` leaves `$name` uninitialized when input function is NULL, causing a PHP fatal

>>> [!note] Migrated issue   Reported by: [ajv009](https://www.drupal.org/user/3653917) Related to !1472 >>> [Tracker] Update Summary: One-line fix with regression tests, patch and fork branch ready. Short Description: ToolsFunctionOutput crashes with an uninitialized typed property when constructed with a NULL input function. Check-in Date: 04/08/2026 Metadata is used by the <a href="https://www.drupalstarforge.ai/" title="AI Tracker">AI Tracker.</a> Docs and additional fields <a href="https://www.drupalstarforge.ai/ai-dashboard/docs" title="AI Issue Tracker Documentation">here</a>. [/Tracker] <h3 id="summary-problem-motivation">Problem/Motivation</h3> <code>Drupal\ai\OperationType\Chat\Tools\ToolsFunctionOutput::__construct()</code> only calls <code>setName()</code> when the input is non-NULL, and <code>$name</code> has no default: <pre><pre>private string $name; public function __construct(?ToolsFunctionInputInterface $input = NULL, string $tool_id = '', array $arguments = []) {   $this-&gt;setToolId($tool_id);   $this-&gt;setInputFunction($input);   if ($input !== NULL) {     $this-&gt;setName($input-&gt;getName());   }   $this-&gt;addArguments($arguments); }</pre></pre>Constructing with <code>NULL</code> leaves the property uninitialized. Any subsequent <code>getName()</code> throws: <pre><pre>Error: Typed property Drupal\ai\OperationType\Chat\Tools\ToolsFunctionOutput::$name        must not be accessed before initialization</pre></pre>This is reachable from <code>OpenAiBasedProviderClientBase::chat()</code> line 360: <pre><pre>$tools[] = new ToolsFunctionOutput(   $input-&gt;getChatTools()-&gt;getFunctionByName($tool['function']['name']),   $tool['id'],   $arguments );</pre></pre>When the LLM returns a tool call for a function name that is not in the current <code>ChatTools</code> input, <code>getFunctionByName()</code> returns NULL and the first argument is NULL. <code>convertToolResponseToObject()</code> then calls <code>getName()</code> on the half-initialized object and kills the entire chat request. Discovered during review of <a href="https://www.drupal.org/project/ai_agents/issues/3560681">ai_agents#3560681</a>: roughly 28% of multi-loop agent runs with Claude Haiku 4.5 hit this fatal when ai_agents filtered a tool out of its available list and the LLM tried to call it anyway. <h4 id="summary-steps-reproduce">Steps to reproduce (required for bugs, but not feature requests)</h4> Minimal unit repro: <pre><pre>$output = new Drupal\ai\OperationType\Chat\Tools\ToolsFunctionOutput(NULL, 'tool_123', []); $output-&gt;getName(); // Fatal: typed property must not be accessed before initialization</pre></pre>Full end-to-end repro (requires ai_agents and an Anthropic-compatible provider): <ol> <li>Install ai, ai_agents, ai_provider_anthropic, key. Configure Claude Haiku 4.5 as the default provider for chat_with_tools.</li> <li>Edit the Taxonomy Agent and set <code>ai_agent:modify_taxonomy_term</code> max_executions to 2 (this requires the ai_agents MR !252 feature for tool ordering constraints).</li> <li>Run the agent with the task "Add these five taxonomy terms to the Tags vocabulary: Apple, Orange, Pineapple, Grape, Mango."</li> <li>The LLM sometimes attempts to call <code>modify_taxonomy_term</code> on loop 3 even though ai_agents has filtered it out of the <code>ChatTools</code> input. When it does, the provider's <code>ToolsFunctionOutput</code> constructor is passed a NULL input and the agent crashes.</li> </ol> Environment used for the repro: <ul> <li>Drupal 11.3.5, PHP 8.3.30</li> <li>ai 1.3.1, ai_agents 1.3.x-dev (with MR !252 branch), ai_provider_anthropic 1.2.2</li> <li>Provider: Anthropic, model <code>claude-haiku-4-5</code></li> <li>Browser/UI: drush scr (no browser involved)</li> </ul> <h3 id="summary-proposed-resolution">Proposed resolution</h3> Default <code>$name</code> to <code>''</code> at the property declaration. One line, backward-compatible, closes the crash path. Patch includes three regression unit tests: baseline (non-NULL input populates name), regression (NULL input no longer crashes on <code>getName()</code>), and <code>setName()</code> after NULL construction. <pre><pre> src/OperationType/Chat/Tools/ToolsFunctionOutput.php                |  9 +++++++- tests/src/Unit/OperationType/Chat/Tools/ToolsFunctionOutputTest.php | 70 ++++++++ 2 files changed, 78 insertions(+), 1 deletion(-)</pre></pre><h3 id="summary-remaining-tasks">Remaining tasks</h3> <ul> <li>Review and commit the one-line property default.</li> <li>Separate follow-up: consider whether <code>OpenAiBasedProviderClientBase::chat()</code> should skip the tool call and log when <code>getFunctionByName()</code> returns NULL.</li> </ul> <h3>Optional: Other details as applicable (e.g., User interface changes, API changes, Data model changes)</h3> No UI, API, or data model changes. <code>getName()</code> still returns <code>string</code>; it now returns <code>''</code> instead of throwing in the NULL-input edge case. <h3 id="summary-ai-usage">AI usage (if applicable)</h3> [ ] AI Assisted Issue This issue was generated with AI assistance, but was reviewed and refined by the creator. [x] AI Assisted Code This code was mainly generated by a human, with AI autocompleting or parts AI generated, but under full human supervision. [ ] AI Generated Code This code was mainly generated by an AI with human guidance, and reviewed, tested, and refined by a human. [ ] Vibe Coded This code was generated by an AI and has only been functionally tested. ``` > Related issue: [Issue #3560681](https://www.drupal.org/node/3560681) > Related issue: [Issue #3582345](https://www.drupal.org/node/3582345)

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