Fix "RuntimeError: memory access out of bounds" bug

Author: samwillis

src/backend/access/common/printtup.c

@@ -499,9 +499,8 @@ StringInfoData json_result;
 EM_JS(void, dispatch_result, (char *res), {
 	// Dispatch the result to JS land
 	var query_result = UTF8ToString(res);
-	out("dispatch_result: '" + query_result + "'");
 	var event = new Module.Event("result", {
-		detail: { result: JSON.parse(query_result) },
+		detail: { result: query_result },
 	});
 	Module.eventTarget.dispatchEvent(event);
 });

src/backend/nodes/nodeFuncs.c

@@ -4000,13 +4000,13 @@ planstate_tree_walker(PlanState *planstate,
 	/* Guard against stack overflow due to overly complex plan trees */
 	check_stack_depth();
 
-	printf("planstate_tree_walker1\n");
+	// printf("planstate_tree_walker1\n");
 
 	/* initPlan-s */
 	if (planstate_walk_subplans(planstate->initPlan, walker, context))
 		return true;
 
-	printf("planstate_tree_walker2\n");
+	// printf("planstate_tree_walker2\n");
 
 	/* lefttree */
 	if (outerPlanState(planstate))
@@ -4015,7 +4015,7 @@ planstate_tree_walker(PlanState *planstate,
 			return true;
 	}
 
-	printf("planstate_tree_walker3\n");
+	// printf("planstate_tree_walker3\n");
 
 	/* righttree */
 	if (innerPlanState(planstate))
@@ -4024,7 +4024,7 @@ planstate_tree_walker(PlanState *planstate,
 			return true;
 	}
 
-	printf("planstate_tree_walker4\n");
+	// printf("planstate_tree_walker4\n");
 
 	/* special child plans */
 	switch (nodeTag(plan))

src/backend/storage/smgr/md.c

@@ -746,8 +746,8 @@ mdwrite(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
 				 errhint("Check free disk space.")));
 	}
 
-	printf("! writing block %u in file \"%s\"\n",
-		blocknum, FilePathName(v->mdfd_vfd));
+	// printf("! writing block %u in file \"%s\"\n",
+	// 	blocknum, FilePathName(v->mdfd_vfd));
 
 	if (!skipFsync && !SmgrIsTemp(reln))
 		register_dirty_segment(reln, forknum, v);

src/backend/tcop/postgres.c

@@ -347,38 +347,39 @@ interactive_getc(void)
  *
  * ----------------
  */
+
+#ifdef EMSCRIPTEN
 EM_ASYNC_JS(char *, await_query, (), {
 	// Await a query from JS land
-	out("await_query: waiting");
 	var event = new Module.Event("waiting");
 	Module.eventTarget.dispatchEvent(event);
-	var { query, qtype } = await new Promise((resolve, reject) => {
+	var query = await new Promise((resolve, reject) => {
 		Module.eventTarget.addEventListener("query", (e) => {
 			resolve(e.detail);
 		}, {once: true});
 	});
-	query = query === undefined ? '' : query;
-	qtype = qtype === undefined ? 'Q' : qtype;
-	out("await_query: got '" + query + "' with type '" + qtype + "'");
-	var combined = qtype + query; // Prepend qtype to query
-	var combined_len = (query.length << 2) + 1;
-	var cstring_ptr = stackAlloc(combined_len);
-	stringToUTF8(combined, cstring_ptr, combined_len);
+	var cstring_ptr = allocateUTF8(query);
 	return cstring_ptr;
 });
+#endif
 
 static int
 EmscriptenBackend(StringInfo inBuf)
 {
-	char *combined = await_query();
-	char qtype = *combined; // First character is qtype
+	char *query = await_query();
+	char qtype = *query; // First character is qtype
+	int qlen = strlen(query);
 
 	resetStringInfo(inBuf);
-	inBuf->data = combined + 1; // Skip qtype character
-	inBuf->len = strlen(inBuf->data);
-	appendStringInfoChar(inBuf, (char) '\0');
+	if (qlen > 1)
+	{
+		appendBinaryStringInfoNT(inBuf, query + 1, qlen - 1);
+		appendStringInfoChar(inBuf, (char) '\0');
+	}
+	
+	free(query);
 
-	return 'Q';
+	return qtype;
 }
 
 /* ----------------