Fix transformJsonBehavior

Commit 1a36bc9dba8 conained some logic that was a little opaque and
could have involved a NULL dereference, as complained about by Coverity.
Make the logic more transparent and in doing so avoid the NULL
dereference.

diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 3cbd5161528e92794c70a7ce452c5c8154138b2c..2f8c5e63fe8297aa9736e15ed725d3e1a58379f5 100644 (file)
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -4072,13 +4072,15 @@ static JsonBehavior *
 transformJsonBehavior(ParseState *pstate, JsonBehavior *behavior,
                      JsonBehaviorType default_behavior)
 {
-   JsonBehaviorType behavior_type;
-   Node       *default_expr;
-
-   behavior_type = behavior ? behavior->btype : default_behavior;
-   default_expr = behavior_type != JSON_BEHAVIOR_DEFAULT ? NULL :
-       transformExprRecurse(pstate, behavior->default_expr);
+   JsonBehaviorType behavior_type = default_behavior;
+   Node       *default_expr = NULL;
 
+   if (behavior)
+   {
+       behavior_type = behavior->btype;
+       if (behavior_type == JSON_BEHAVIOR_DEFAULT)
+           default_expr = transformExprRecurse(pstate, behavior->default_expr);
+   }
    return makeJsonBehavior(behavior_type, default_expr);
 }