[#24055] YSQL: fix pg_hint_plan regression with executing prepared st…

…atement

Summary:
Fix a regression introduced in 5523770 where the hints were missed out when the query was recompiled without going through semantic analysis again.

Move the query string - query tree consistency check to the hint_table specific code.  In the other case, the hints are directly taken from the query string without using the location info in the query tree hence the mismatch is harmless.

**pg15: there's nothing to merge/port to the pg15 branch.**
Jira: DB-12947

Test Plan:
  ./yb_build.sh --java-test 'org.yb.pgsql.TestPgMisc#testPgHintPlanExtendedQuery'
  ./yb_build.sh --java-test 'org.yb.pgsql.TestYbBackup#testPgHintPlan'
  ./yb_build.sh --java-test 'org.yb.pgsql.TestPgRegressThirdPartyExtensionsPgHintPlan'

Jenkins: test regex: .*PgHintPlan.*

Reviewers: tnayak

Reviewed By: tnayak

Subscribers: smishra, yql

Differential Revision: https://phorge.dev.yugabyte.com/D38265

src/postgres/third-party-extensions/pg_hint_plan/pg_hint_plan.c

@@ -1931,12 +1931,6 @@ get_query_string(ParseState *pstate, Query *query, Query **jumblequery)
 	else if (!jumblequery && pstate && pstate->p_sourcetext != p &&
 			 strcmp(pstate->p_sourcetext, p) != 0)
 		p = NULL;
-	/*
-	 * YB note: don't assume it is the top-level query when pstate is NULL and
-	 * the query tree does not have the source location.
-	 */
-	else if (!pstate && query->stmt_location <= 0 && query->stmt_len <= 0)
-		p = NULL;
 
 	return p;
 }
@@ -2901,6 +2895,14 @@ get_current_hint_string(ParseState *pstate, Query *query)
 
 		query_str = get_query_string(pstate, query, &jumblequery);
 
+		/*
+		 * YB note: don't assume it is the top-level query when pstate is NULL
+		 * and the query tree does not have the source location.
+		 */
+		if (!pstate && query->stmt_location <= 0 && query->stmt_len <= 0 &&
+			query_str == debug_query_string)
+			query_str = NULL;
+
 		/* If this query is not for hint, just return */
 		if (!query_str)
 			return;