fix: respect system setting for tracebacks

closes https://github.com/frappe/frappe/issues/19826

frappe/app.py

@@ -284,6 +284,8 @@ def handle_exception(e):
 		or (frappe.local.request.path.startswith("/api/") and not accept_header.startswith("text"))
 	)
 
+	allow_traceback = frappe.get_system_settings("allow_error_traceback") if frappe.db else False
+
 	if not frappe.session.user:
 		# If session creation fails then user won't be unset. This causes a lot of code that
 		# assumes presence of this to fail. Session creation fails => guest or expired login
@@ -338,7 +340,7 @@ def handle_exception(e):
 	else:
 		traceback = "<pre>" + sanitize_html(frappe.get_traceback()) + "</pre>"
 		# disable traceback in production if flag is set
-		if frappe.local.flags.disable_traceback and not frappe.local.dev_server:
+		if frappe.local.flags.disable_traceback or not allow_traceback and not frappe.local.dev_server:
 			traceback = ""
 
 		frappe.respond_as_web_page(

frappe/utils/response.py

@@ -29,9 +29,7 @@ if TYPE_CHECKING:
 
 def report_error(status_code):
 	"""Build error. Show traceback in developer mode"""
-	allow_traceback = (
-		cint(frappe.db.get_system_setting("allow_error_traceback")) if frappe.db else True
-	)
+	allow_traceback = frappe.get_system_settings("allow_error_traceback") if frappe.db else False
 	if (
 		allow_traceback
 		and (status_code != 404 or frappe.conf.logging)

frappe/www/error.py

@@ -10,7 +10,13 @@ def get_context(context):
 	if frappe.flags.in_migrate:
 		return
 
+	allow_traceback = frappe.get_system_settings("allow_error_traceback") if frappe.db else False
+
 	context.error_title = context.error_title or _("Uncaught Server Exception")
 	context.error_message = context.error_message or _("There was an error building this page")
 
-	return {"error": frappe.get_traceback().replace("<", "&lt;").replace(">", "&gt;")}
+	return {
+		"error": frappe.get_traceback().replace("<", "&lt;").replace(">", "&gt;")
+		if allow_traceback
+		else ""
+	}