diff --git a/contrib/postgres_fdw/deparse.c b/contrib/postgres_fdw/deparse.c
index 548ae66119..19f928ec59 100644
--- a/contrib/postgres_fdw/deparse.c
+++ b/contrib/postgres_fdw/deparse.c
@@ -1531,7 +1531,7 @@ deparseFromExprForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel,
 			{
 				Assert(fpinfo->jointype == JOIN_INNER);
 				Assert(fpinfo->joinclauses == NIL);
-				appendStringInfoString(buf, join_sql_o.data);
+				appendBinaryStringInfo(buf, join_sql_o.data, join_sql_o.len);
 				return;
 			}
 		}
@@ -1552,7 +1552,7 @@ deparseFromExprForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel,
 			{
 				Assert(fpinfo->jointype == JOIN_INNER);
 				Assert(fpinfo->joinclauses == NIL);
-				appendStringInfoString(buf, join_sql_i.data);
+				appendBinaryStringInfo(buf, join_sql_i.data, join_sql_i.len);
 				return;
 			}
 		}
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index 29e2681484..dbd7dd9bcd 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -2290,7 +2290,7 @@ ExecBuildSlotValueDescription(Oid reloid,
 			/* truncate if needed */
 			vallen = strlen(val);
 			if (vallen <= maxfieldlen)
-				appendStringInfoString(&buf, val);
+				appendBinaryStringInfo(&buf, val, vallen);
 			else
 			{
 				vallen = pg_mbcliplen(val, vallen, maxfieldlen);
@@ -2309,7 +2309,7 @@ ExecBuildSlotValueDescription(Oid reloid,
 	if (!table_perm)
 	{
 		appendStringInfoString(&collist, ") = ");
-		appendStringInfoString(&collist, buf.data);
+		appendBinaryStringInfo(&collist, buf.data, buf.len);
 
 		return collist.data;
 	}
diff --git a/src/backend/executor/execPartition.c b/src/backend/executor/execPartition.c
index f49a48adb6..729dc396a9 100644
--- a/src/backend/executor/execPartition.c
+++ b/src/backend/executor/execPartition.c
@@ -1406,7 +1406,7 @@ ExecBuildSlotPartitionKeyDescription(Relation rel,
 		/* truncate if needed */
 		vallen = strlen(val);
 		if (vallen <= maxfieldlen)
-			appendStringInfoString(&buf, val);
+			appendBinaryStringInfo(&buf, val, vallen);
 		else
 		{
 			vallen = pg_mbcliplen(val, vallen, maxfieldlen);
diff --git a/src/backend/storage/lmgr/deadlock.c b/src/backend/storage/lmgr/deadlock.c
index 9abc9d778f..990d48377d 100644
--- a/src/backend/storage/lmgr/deadlock.c
+++ b/src/backend/storage/lmgr/deadlock.c
@@ -1115,7 +1115,7 @@ DeadLockReport(void)
 	}
 
 	/* Duplicate all the above for the server ... */
-	appendStringInfoString(&logbuf, clientbuf.data);
+	appendBinaryStringInfo(&logbuf, clientbuf.data, clientbuf.len);
 
 	/* ... and add info about query strings */
 	for (i = 0; i < nDeadlockDetails; i++)
diff --git a/src/backend/utils/adt/ri_triggers.c b/src/backend/utils/adt/ri_triggers.c
index 44a6eef5bb..8c895459c3 100644
--- a/src/backend/utils/adt/ri_triggers.c
+++ b/src/backend/utils/adt/ri_triggers.c
@@ -927,7 +927,7 @@ RI_FKey_cascade_upd(PG_FUNCTION_ARGS)
 			queryoids[i] = pk_type;
 			queryoids[j] = pk_type;
 		}
-		appendStringInfoString(&querybuf, qualbuf.data);
+		appendBinaryStringInfo(&querybuf, qualbuf.data, qualbuf.len);
 
 		/* Prepare and save the plan */
 		qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys * 2, queryoids,
@@ -1106,7 +1106,7 @@ ri_set(TriggerData *trigdata, bool is_set_null)
 			qualsep = "AND";
 			queryoids[i] = pk_type;
 		}
-		appendStringInfoString(&querybuf, qualbuf.data);
+		appendBinaryStringInfo(&querybuf, qualbuf.data, qualbuf.len);
 
 		/* Prepare and save the plan */
 		qplan = ri_PlanCheck(querybuf.data, riinfo->nkeys, queryoids,
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 4ca0ed2bbb..0c58f1f109 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -2804,9 +2804,9 @@ pg_get_functiondef(PG_FUNCTION_ARGS)
 		appendStringInfoChar(&dq, 'x');
 	appendStringInfoChar(&dq, '$');
 
-	appendStringInfoString(&buf, dq.data);
+	appendBinaryStringInfo(&buf, dq.data, dq.len);
 	appendStringInfoString(&buf, prosrc);
-	appendStringInfoString(&buf, dq.data);
+	appendBinaryStringInfo(&buf, dq.data, dq.len);
 
 	appendStringInfoChar(&buf, '\n');
 
@@ -2930,7 +2930,7 @@ print_function_rettype(StringInfo buf, HeapTuple proctup)
 		appendStringInfoString(&rbuf, format_type_be(proc->prorettype));
 	}
 
-	appendStringInfoString(buf, rbuf.data);
+	appendBinaryStringInfo(buf, rbuf.data, rbuf.len);
 }
 
 /*
@@ -5682,7 +5682,7 @@ get_target_list(List *targetList, deparse_context *context,
 		}
 
 		/* Add the new field */
-		appendStringInfoString(buf, targetbuf.data);
+		appendBinaryStringInfo(buf, targetbuf.data, targetbuf.len);
 	}
 
 	/* clean up */
@@ -9987,7 +9987,7 @@ get_from_clause(Query *query, const char *prefix, deparse_context *context)
 			}
 
 			/* Add the new item */
-			appendStringInfoString(buf, itembuf.data);
+			appendBinaryStringInfo(buf, itembuf.data, itembuf.len);
 
 			/* clean up */
 			pfree(itembuf.data);
diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
index d43c3055f3..5e629d29ea 100644
--- a/src/backend/utils/adt/xml.c
+++ b/src/backend/utils/adt/xml.c
@@ -559,7 +559,7 @@ xmlconcat(List *args)
 					   0,
 					   global_standalone);
 
-		appendStringInfoString(&buf2, buf.data);
+		appendBinaryStringInfo(&buf2, buf.data, buf.len);
 		buf = buf2;
 	}
 
@@ -1879,7 +1879,8 @@ xml_errorHandler(void *data, xmlErrorPtr error)
 	if (xmlerrcxt->strictness == PG_XML_STRICTNESS_LEGACY)
 	{
 		appendStringInfoLineSeparator(&xmlerrcxt->err_buf);
-		appendStringInfoString(&xmlerrcxt->err_buf, errorBuf->data);
+		appendBinaryStringInfo(&xmlerrcxt->err_buf, errorBuf->data,
+							   errorBuf->len);
 
 		pfree(errorBuf->data);
 		pfree(errorBuf);
@@ -1897,7 +1898,8 @@ xml_errorHandler(void *data, xmlErrorPtr error)
 	if (level >= XML_ERR_ERROR)
 	{
 		appendStringInfoLineSeparator(&xmlerrcxt->err_buf);
-		appendStringInfoString(&xmlerrcxt->err_buf, errorBuf->data);
+		appendBinaryStringInfo(&xmlerrcxt->err_buf, errorBuf->data,
+							   errorBuf->len);
 
 		xmlerrcxt->err_occurred = true;
 	}
@@ -2874,7 +2876,7 @@ schema_to_xml_internal(Oid nspid, const char *xmlschema, bool nulls,
 		subres = table_to_xml_internal(relid, NULL, nulls, tableforest,
 									   targetns, false);
 
-		appendStringInfoString(result, subres->data);
+		appendBinaryStringInfo(result, subres->data, subres->len);
 		appendStringInfoChar(result, '\n');
 	}
 
@@ -3049,7 +3051,7 @@ database_to_xml_internal(const char *xmlschema, bool nulls,
 		subres = schema_to_xml_internal(nspid, NULL, nulls,
 										tableforest, targetns, false);
 
-		appendStringInfoString(result, subres->data);
+		appendBinaryStringInfo(result, subres->data, subres->len);
 		appendStringInfoChar(result, '\n');
 	}