refs #4679 - fix @Schema#implementation resolving for OAS 3.1

Author: micryc

modules/swagger-core/src/main/java/io/swagger/v3/core/jackson/ModelResolver.java

@@ -683,6 +683,9 @@ public Schema resolve(AnnotatedType annotatedType, ModelConverterContext context
                                             !(a instanceof io.swagger.v3.oas.annotations.media.ArraySchema)) {
                                 ctxAnnotations31List.add(a);
                             }
+                            if ((ctxSchema != null) && (!ctxSchema.implementation().equals(Void.class) || StringUtils.isNotEmpty(ctxSchema.type()))) {
+                                    ctxAnnotations31List.add(a);
+                                }
                         }
                         ctxAnnotation31 = ctxAnnotations31List.toArray(new Annotation[ctxAnnotations31List.size()]);
                     }

modules/swagger-core/src/test/java/io/swagger/v3/core/resolving/Ticket4679Test.java

@@ -0,0 +1,55 @@
+package io.swagger.v3.core.resolving;
+
+import io.swagger.v3.core.converter.ModelConverters;
+import io.swagger.v3.core.matchers.SerializationMatchers;
+import io.swagger.v3.core.util.Yaml;
+import io.swagger.v3.core.util.Yaml31;
+import io.swagger.v3.oas.annotations.media.Schema;
+import org.testng.annotations.Test;
+
+import java.util.Map;
+
+public class Ticket4679Test extends SwaggerTestBase{
+
+    @Test(description = "Custom schema implementation in property overrides type value")
+    public void testCustomSchemaImplementation() {
+
+        String expectedYaml = "ModelWithCustomSchemaImplementationInProperty:\n" +
+                "  properties:\n" +
+                "    exampleField:\n" +
+                "      type: integer\n" +
+                "      format: int32\n" +
+                "    secondExampleField:\n" +
+                "      type: string\n";
+
+        Map<String, io.swagger.v3.oas.models.media.Schema> stringSchemaMap = ModelConverters.getInstance(true).readAll(ModelWithCustomSchemaImplementationInProperty.class);
+        SerializationMatchers.assertEqualsToYaml31(stringSchemaMap, expectedYaml);
+    }
+
+    static class ModelWithCustomSchemaImplementationInProperty {
+
+        @Schema(implementation = Integer.class)
+        private String exampleField;
+
+        @Schema(type = "string")
+        private Integer secondExampleField;
+
+        public String getExampleField() {
+            return exampleField;
+        }
+
+        public void setExampleField(String exampleField) {
+            this.exampleField = exampleField;
+        }
+
+        public Integer getSecondExampleField() {
+            return secondExampleField;
+        }
+
+        public void setSecondExampleField(Integer secondExampleField) {
+            this.secondExampleField = secondExampleField;
+        }
+
+
+    }
+}