Follow the change of ExplainState.

ExplainState was changed at 9.4.1 and 9.3.6. This change breaks where
using es->grouping_stack so change the way to access it so that one
source supports both before and after the change was made. After all,
for instance, PG 9.4.0 and 9.4.1 cannot be able to share the same
pg_store_plans binary.

diff --git a/pgsp_explain.c b/pgsp_explain.c
index 9cd025f..fa986b8 100644 (file)
--- a/pgsp_explain.c
+++ b/pgsp_explain.c
@@ -22,6 +22,13 @@ static void pgspExplainProperty(const char *qlabel, const char *value, bool nume
                                                        ExplainState *es);
 static void pgspExplainJSONLineEnding(ExplainState *es);
 
+/* ExplainState is modified at 9.4.1 and 9.3.6  */
+#if PG_VERSION_NUM >= 90401 || (PG_VERSION_NUM >= 90306 && PG_VERSION_NUM < 90400)
+#define GROUPING_STACK(es) ((es)->extra->groupingstack)
+#else
+#define GROUPING_STACK(es) ((es)->grouping_stack)
+#endif
+
 void
 pgspExplainTriggers(ExplainState *es, QueryDesc *queryDesc)
 {
@@ -64,7 +71,7 @@ pgspExplainOpenGroup(const char *objtype, const char *labelname,
        }
        appendStringInfoChar(es->str, labeled ? '{' : '[');
        
-       es->grouping_stack = lcons_int(0, es->grouping_stack);
+       GROUPING_STACK(es) = lcons_int(0, GROUPING_STACK(es));
        es->indent++;
 }
 
@@ -76,7 +83,7 @@ pgspExplainCloseGroup(const char *objtype, const char *labelname,
        appendStringInfoChar(es->str, '\n');
        appendStringInfoSpaces(es->str, 2 * es->indent);
        appendStringInfoChar(es->str, labeled ? '}' : ']');
-       es->grouping_stack = list_delete_first(es->grouping_stack);
+       GROUPING_STACK(es) = list_delete_first(GROUPING_STACK(es));
 }
 
 static void
@@ -158,10 +165,10 @@ static void
 pgspExplainJSONLineEnding(ExplainState *es)
 {
        Assert(es->format == EXPLAIN_FORMAT_JSON);
-       if (linitial_int(es->grouping_stack) != 0)
+       if (linitial_int(GROUPING_STACK(es)) != 0)
                appendStringInfoChar(es->str, ',');
        else
-               linitial_int(es->grouping_stack) = 1;
+               linitial_int(GROUPING_STACK(es)) = 1;
        appendStringInfoChar(es->str, '\n');
 }