@Pattern on @RequestParam List<@Pattern String> leaks to sibling array parameters (incomplete fix from #3259)

[vikas72878]

Describe the bug

• When multiple @RequestParam parameters of type List<@pattern String> are declared on a controller method, and each has a different @pattern regex, springdoc applies the last parameter's pattern to all sibling array parameters in the generated OpenAPI spec.

• This was partially fixed for @ParameterObject DTOs in PR #3259, but the same bug still occurs for @RequestParam parameters declared directly on controller methods.

To Reproduce

Spring Boot: 4.0.7
springdoc-openapi: 3.0.3 (springdoc-openapi-starter-webmvc-ui)
Minimal controller:

@RestController
@RequestMapping("/demo")
public class DemoController {
    @GetMapping
    public List<String> search(
        @RequestParam(required = false) List<@Pattern(regexp = "^\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\S*") String> versions,
        @RequestParam(required = false) List<@Pattern(regexp = "^[a-zA-Z0-9]{1,255}$") String> storeNbrs,
        @RequestParam(required = false) List<@Pattern(regexp = "^[a-zA-Z]+[a-z_A-Z]*[a-zA-Z]+$") String> locationNames
    ) {
        return List.of();
    }
}

Actual result (/v3/api-docs):

All three parameters get the same pattern (from locationNames):

"parameters": [
    {
        "name": "versions",
        "in": "query",
        "schema": {
            "type": "array",
            "items": {
                "type": "string",
                "pattern": "^[a-zA-Z]+[a-z_A-Z]*[a-zA-Z]+$"
            }
        }
    },
    {
        "name": "storeNbrs",
        "in": "query",
        "schema": {
            "type": "array",
            "items": {
                "type": "string",
                "pattern": "^[a-zA-Z]+[a-z_A-Z]*[a-zA-Z]+$"
            }
        }
    },
    {
        "name": "locationNames",
        "in": "query",
        "schema": {
            "type": "array",
            "items": {
                "type": "string",
                "pattern": "^[a-zA-Z]+[a-z_A-Z]*[a-zA-Z]+$"
            }
        }
    }
]

Expected result:

Each parameter should have its own pattern:

"parameters": [
    {
        "name": "versions",
        "in": "query",
        "schema": {
            "type": "array",
            "items": {
                "type": "string",
                "pattern": "^\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\S*"
            }
        }
    },
    {
        "name": "storeNbrs",
        "in": "query",
        "schema": {
            "type": "array",
            "items": {
                "type": "string",
                "pattern": "^[a-zA-Z0-9]{1,255}$"
            }
        }
    },
    {
        "name": "locationNames",
        "in": "query",
        "schema": {
            "type": "array",
            "items": {
                "type": "string",
                "pattern": "^[a-zA-Z]+[a-z_A-Z]*[a-zA-Z]+$"
            }
        }
    }
]

Expected behavior

Each @RequestParam List<@pattern String> parameter should have its own @pattern regex applied to the items schema independently. The pattern from one parameter should not leak to siblings.

Additional context

PR #3259 fixed this for @ParameterObject DTOs by addressing how annotated generic types are resolved. The same root cause (shared/mutated AnnotatedType state) appears to still affect @RequestParam parameters declared directly on controller methods.

Swagger UI rejects valid input with Value must follow pattern ... because it validates against the wrong (leaked) pattern.