Accept decimal-int-string arguments for %d printf placeholders in strict mode

[phpstan-bot]

Summary

In strict printf placeholder mode (checkStrictPrintfPlaceholderTypes), passing an integer-valued string such as '42' to a %d placeholder was reported as an error. As discussed in the issue, a decimal-int-string is printed by %d without any lossy conversion, so it should be accepted. This change allows decimal-int-string for %d-family placeholders while continuing to reject numeric-string and other strings that %d would trim or alter.

Changes

• src/Rules/Functions/PrintfPlaceholder.php: for the int accepting type in strict mode, accept int or decimal-int-string (string & AccessoryDecimalIntegerStringType) instead of only int. Mirrors how the float case already accepts numeric-string.
• tests/PHPStan/Rules/Functions/data/printf-param-types.php and PrintfParameterTypeRuleTest.php: added regression cases for decimal-int-string (OK), numeric-string (error), non-decimal-int-string (error), and constant strings '42'/'-1'/'0' (OK) vs '00'/'+1' (error).

Root cause

The strict int branch checked only (new IntegerType())->accepts($argumentType, true)->yes(), which rejects any string type. %d casts its argument to an integer; for a decimal-int-string this cast is lossless (the string already is the canonical decimal representation of an integer), so there is no reason to report it. The fix reuses the existing AccessoryDecimalIntegerStringType accessory type — the same abstraction PHPStan uses to decide whether a string array key is cast to int.

Analogous cases probed:

• float (%f, %e, %g, …): already accepts numeric-string, which is a superset of decimal-int-string, so it was already correct — no change needed.
• strict-int (width/precision, e.g. %*d): intentionally kept int-only; these are a deliberately stricter category and the reported issue concerns only the %d value slot.
• Constant strings: '42', '-1', '0' are recognized as decimal-int-string by ConstantStringType::isDecimalIntegerString(), so they are now accepted too (covering the printf('%d', '42') example from the discussion), while '00' / '+1' / '1.23' remain errors.

Test

PrintfParameterTypeRuleTest::testStrict gains cases asserting that decimal-int-string and constant int-strings are accepted for %d, while numeric-string, non-decimal-int-string, and non-canonical constant strings still produce errors. The non-strict test continues to pass unchanged. The regression fails without the source change (the decimal-int-string case is reported as an unexpected error).

Fixes phpstan/phpstan#13609