[cpp] Fix Nested Map & Additional Properties Support

[winrid]

Fixes #12737

• Basically support for map<string, map<string, string>> was broken.
• Also fixes "additionalProperties" and adds a test.

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Summary by cubic

Fix nested map generation in C++ (Qt, RestSDK, Tiny) so map<string, map<string, string>> types resolve and compile. Also add additionalProperties support to cpp-restsdk models to capture and serialize unknown fields. Fixes #12737.

• Bug Fixes

  • Resolve $ref-ed map schemas in CppQtAbstractCodegen, CppRestSdkClientCodegen, and CppTinyClientCodegen to properly type nested maps.
  • Generate correct map types (QMap/std::map) in type declarations and defaults; add std::map mapping and includes in cpp-tiny.
  • Update cpp-tiny templates to use actual map types in getters, setters, and fields (no hard-coded <string, string>).
  • Add a nested-maps test spec and extend petstore with StringMap, NestedStringMap, and PetStatistics; generate sample models to validate JSON (de)serialization.

• New Features

  • cpp-restsdk: support additionalProperties on models with defined properties; store unknown keys in std::map<utility::string_t, web::json::value> and include them in JSON (de)serialization; add SchemaWithPropsAndAddlProps sample.

^{Written for commit d5f82ef. Summary will update on new commits.}

[cubic-dev-ai]

1 issue found across 23 files

Prompt for AI agents (all issues)

Check if these issues are valid — if so, understand the root cause of each and fix them.


<file name="modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppTinyClientCodegen.java">

<violation number="1" location="modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppTinyClientCodegen.java:281">
P1: Potential NullPointerException: `ModelUtils.getAdditionalProperties(resolved)` can return null when `additionalProperties` is a boolean or not present. Consider adding a null check before calling `getTypeDeclaration(inner)`.</violation>
</file>

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[cubic-dev-ai]

1 issue found across 7 files (changes from recent commits).

Prompt for AI agents (all issues)

Check if these issues are valid — if so, understand the root cause of each and fix them.


<file name="modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppRestSdkClientCodegen.java">

<violation number="1" location="modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppRestSdkClientCodegen.java:398">
P2: Method inserted in wrong location - this separates the existing JavaDoc for `getTypeDeclaration()` from its method. The `isPureMapSchema()` helper should be placed either before that JavaDoc block or after the `getTypeDeclaration()` method to preserve the documentation association.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[winrid]

Ready for review @muttleyxd @aminya