Loading openapi schema with default: null generates invalid memory address or nil pointer dereference

[filipebreda]

restish --version
dev-2024-04-21-17:50

When hash := items.GoLow().Hash() is called, libopenapi considers !s.Default.IsEmpty() to be true, I assume bcause it is defined in the openapi file, proceeding to pass a nil value low.GenerateHashString(s.Default.Value).

--- FAIL: TestLoader (0.01s)
    --- FAIL: TestLoader/petstore (0.00s)
panic: runtime error: invalid memory address or nil pointer dereference [recovered]
	panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x98 pc=0x6f4623]

goroutine 80 [running]:
testing.tRunner.func1.2({0xc324a0, 0x13915b0})
	/usr/local/go/src/testing/testing.go:1545 +0x238
testing.tRunner.func1()
	/usr/local/go/src/testing/testing.go:1548 +0x397
panic({0xc324a0?, 0x13915b0?})
	/usr/local/go/src/runtime/panic.go:914 +0x21f
github.com/pb33f/libopenapi/datamodel/low.GenerateHashString({0x0, 0x0})
	/home/filipe/go/pkg/mod/github.com/pb33f/libopenapi@v0.9.7/datamodel/low/extraction_functions.go:707 +0x83
github.com/pb33f/libopenapi/datamodel/low/base.(*Schema).Hash(0xc0001b0000)
	/home/filipe/go/pkg/mod/github.com/pb33f/libopenapi@v0.9.7/datamodel/low/base/schema.go:249 +0x18fb
github.com/pb33f/libopenapi/datamodel/low/base.(*SchemaProxy).Hash(0xc000168b40)
	/home/filipe/go/pkg/mod/github.com/pb33f/libopenapi@v0.9.7/datamodel/low/base/schema_proxy.go:146 +0x105
github.com/pb33f/libopenapi/datamodel/low.GenerateHashString({0xc8bc80, 0xc000168b40})
	/home/filipe/go/pkg/mod/github.com/pb33f/libopenapi@v0.9.7/datamodel/low/extraction_functions.go:703 +0x1e2
github.com/pb33f/libopenapi/datamodel/low/base.(*Schema).Hash(0xc000436800)
	/home/filipe/go/pkg/mod/github.com/pb33f/libopenapi@v0.9.7/datamodel/low/base/schema.go:312 +0x2cdc
github.com/danielgtaylor/restish/openapi.renderSchemaInternal(0xc0003d2a00, {0x0, 0x0}, 0x0, 0xc069e0?)
	/home/filipe/Projects/restish/openapi/schema.go:170 +0x138d
github.com/danielgtaylor/restish/openapi.renderSchema(...)
	/home/filipe/Projects/restish/openapi/schema.go:56
github.com/danielgtaylor/restish/openapi.openapiOperation(_, {_, _}, _, _, _)
	/home/filipe/Projects/restish/openapi/openapi.go:516 +0x2af3
github.com/danielgtaylor/restish/openapi.loadOpenAPI3({0xee1080, 0xc0002309d0}, 0x58d629?, 0xc000618510, 0xd354ea?)
	/home/filipe/Projects/restish/openapi/openapi.go:618 +0x16a5
github.com/danielgtaylor/restish/openapi.(*loader).Load(_, {{0xd2089b, 0x4}, {0x0, 0x0}, 0x0, {0xd208a2, 0xf}, {0x0, 0x0}, ...}, ...)
	/home/filipe/Projects/restish/openapi/openapi.go:803 +0x19c
github.com/danielgtaylor/restish/openapi.TestLoader.func1(0xc0005429c0?)
	/home/filipe/Projects/restish/openapi/openapi_test.go:233 +0x466
testing.tRunner(0xc0005429c0, 0xc000230490)
	/usr/local/go/src/testing/testing.go:1595 +0xff
created by testing.(*T).Run in goroutine 613
	/usr/local/go/src/testing/testing.go:1648 +0x3ad
exit status 2
FAIL	github.com/danielgtaylor/restish/openapi	0.026s

It's reproducible by adjusting openapi/testdata and running go test.

diff --git a/openapi/testdata/petstore/openapi.yaml b/openapi/testdata/petstore/openapi.yaml
index e0f4553..763a238 100644
--- a/openapi/testdata/petstore/openapi.yaml
+++ b/openapi/testdata/petstore/openapi.yaml
@@ -86,6 +86,8 @@ components:
           type: integer
           format: int64
         name:
+          nullable: true
+          default: null
           type: string
         tag:
           type: string

I checked the libopenapi repository and the code which is causing this issue has been changed, meaning a dependency upgrade might be in order.

Cheers.