Guard text field maxlength check against non-scalar values

[cbravobernal]

Description

The text and textarea field types validate a submitted value against their configured maxlength by calling acf_strlen( $value ). That helper runs string operations (wp_unslash, str_replace, mb_strlen) directly on the value.

A form submission can deliver a non-scalar value (for example an array) for one of these fields. When that happens with a maxlength set, the maxlength check ran a string operation on an array and emitted an Array to string conversion notice. A non-scalar value is not valid text and should simply be treated as invalid rather than producing a diagnostic.

Change

Guard the maxlength check with is_scalar( $value ) in both field types so a non-scalar value skips the string-length operation:

• includes/fields/class-acf-field-text.php — validate_value()
• includes/fields/class-acf-field-textarea.php — validate_value()

Behavior for normal string values is unchanged. A non-scalar value preserves the passed validity state, matching the field's existing handling of values that are not valid text. The same code path exists in the upstream-derived source, so the same guard applies there.

Tests

Added regression tests asserting that validating a non-scalar value with a maxlength set does not emit an array-to-string conversion and preserves the passed validity state:

• Test_ACF_Field_Text::test_validate_value_array_with_maxlength_does_not_convert
• Test_ACF_Field_Textarea::test_validate_value_array_with_maxlength_does_not_convert

The tests fail against the unpatched code (the conversion notice fires) and pass with the guard.

Verification

• composer test:php -- --filter 'Field_Text' — green (23 tests)
• composer test:php — green (2266 tests, 4306 assertions)
• composer test:phpstan — no errors
• vendor/bin/phpcs — clean on the changed test files; the changed source lines add no new findings (pre-existing upstream-derived style findings are unchanged)

Use of AI Tools

This change was authored with Claude Code under human direction. The author reviewed and takes responsibility for the change.

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