move fix into get_job_kwargs

awx/main/models/workflow.py

@@ -335,7 +335,9 @@ class WorkflowJobNode(WorkflowNodeBase):
             # or labels, because they do not propogate WFJT-->node at all
 
             # Combine WFJT prompts with node here, WFJT at higher level
-            node_prompts_data.update(wj_prompts_data)
+            # Empty string values on the workflow job (e.g. from IaC setting limit: "")
+            # should not override a node's explicit non-empty prompt value
+            node_prompts_data.update({k: v for k, v in wj_prompts_data.items() if v != ''})
             accepted_fields, ignored_fields, errors = ujt_obj._accept_or_ignore_job_kwargs(**node_prompts_data)
             if errors:
                 logger.info(

awx/main/utils/common.py

@@ -476,7 +476,7 @@ class NullablePromptPseudoField:
         return instance.char_prompts.get(self.field_name, None)
 
     def __set__(self, instance, value):
-        if value in (None, {}, ''):
+        if value in (None, {}):
             instance.char_prompts.pop(self.field_name, None)
         else:
             instance.char_prompts[self.field_name] = value