Add missing code in staging

c/jsonschema.c

@@ -1108,7 +1108,27 @@ static JSValueSpec *resolveRef(JsonValidator *validator, ValidityException *pend
 static VResult validateJSONSimple(JsonValidator *validator,
                                   Json *value, JSValueSpec *valueSpec, int depth, EvalSet *evalSetList){
   if (jsonIsNull(value)){
-    return validateType(validator,JSTYPE_NULL,valueSpec,depth+1);
+    VResult typeResult = validateType(validator,JSTYPE_NULL,valueSpec,depth+1);
+    if (vStatusValid(typeResult.status)) {
+      return typeResult;
+    } else if (validator->allowStringToBeNull) {
+      // FIXME: Some users were relying upon a bug we fixed, where an empty value would be treated as a string.
+      // TODO: Remove this in v3, we should not keep this bug compatability forever.
+      if (((1 << JSTYPE_STRING) & valueSpec->typeMask) != 0){
+        Json *emptyStringJson = (Json*)safeMalloc(sizeof(Json), "Empty String JSON");
+        emptyStringJson->type = JSON_TYPE_STRING;
+        char emptyString[1] = {0};
+        emptyStringJson->data.string = emptyString;
+        // Check if schema is okay with an "empty string" as the previous bug had null be empty string.
+        VResult stringResult = validateJSONString(validator,emptyStringJson,valueSpec,depth+1);
+        safeFree((char*)emptyStringJson, sizeof(Json));
+        return stringResult;
+      } else{
+        return simpleFailure(validator, "string cannot be null for %s\n", validatorAccessPath(validator));
+      }                   
+    } else {
+      return typeResult;
+    }
   } else if (jsonIsBoolean(value)){
     return validateType(validator,JSTYPE_BOOLEAN,valueSpec,depth+1);
   } else if (jsonIsObject(value)){
@@ -1306,14 +1326,34 @@ static VResult validateJSON(JsonValidator *validator,
     /* As we go through the valid enum values, record them in comma separated
      * form for displaying at the tail end of the error message.
      */
+
+    bool nullToString = false;
+    Json *emptyStringJson;
+    if (jsonIsNull(value)) {
+      VResult typeResult = validateType(validator,JSTYPE_NULL,valueSpec,depth+1);
+      if ((!vStatusValid(typeResult.status)) && (validator->allowStringToBeNull)) {
+        // FIXME: Some users were relying upon a bug we fixed, where an empty value would be treated as a string.
+        // TODO: Remove this in v3, we should not keep this bug compatability forever.
+        if (((1 << JSTYPE_STRING) & valueSpec->typeMask) != 0){
+          emptyStringJson = (Json*)safeMalloc(sizeof(Json), "Empty String JSON");
+          emptyStringJson->type = JSON_TYPE_STRING;
+          char emptyString[1] = {0};
+          emptyStringJson->data.string = emptyString;
+          nullToString = true;
+        }
+      }
+    }
+
     unsigned int validValuesMaxSize = (valueSpec->enumeratedValuesCount * (sizeof(Json*) + 3)) + 1;
     char *validValues = SLHAlloc(validator->evalHeap, validValuesMaxSize);
     if (validValues) {
       memset(validValues, 0, validValuesMaxSize);
     }
+
+    Json *whichValue = nullToString == true ? emptyStringJson : value;
     for (int ee=0; ee<valueSpec->enumeratedValuesCount; ee++){
       Json *enumValue = valueSpec->enumeratedValues[ee];
-      if (jsonEquals(value,enumValue)){
+      if (jsonEquals(whichValue,enumValue)){
         matched = true;
         break;
       }
@@ -1337,6 +1377,9 @@ static VResult validateJSON(JsonValidator *validator,
         strcat(validValues, ", ");
       }
     }
+    if (nullToString) {
+      safeFree((char*)emptyStringJson, sizeof(Json));
+    }
     if (!matched){
       if (validValues && strlen(validValues) > 0) {
         return simpleFailure(validator,"no matching enum value at %s; expecting one of values '[%s]' of type '%s'",
@@ -1420,6 +1463,8 @@ static VResult validateJSON(JsonValidator *validator,
 int jsonValidateSchema(JsonValidator *validator, Json *value, JsonSchema *topSchema,
                        JsonSchema **otherSchemas, int otherSchemaCount){
   int result = 0;
+  validator->allowStringToBeNull = true;
+
   if (setjmp(validator->recoveryData) == 0) {  /* normal execution */
     validator->topSchema = topSchema;
     validator->otherSchemas = otherSchemas;

h/jsonschema.h

@@ -117,6 +117,7 @@ typedef struct JsonValidator_tag {
   int         fileRegexError;
   jmp_buf     recoveryData;
   ShortLivedHeap *evalHeap;
+  bool        allowStringToBeNull;
 } JsonValidator;
 
 #define JSON_SCHEMA_DRAFT_4 400