diff --git a/contrib/hstore/hstore_io.c b/contrib/hstore/hstore_io.c
index fb72bb6cfe..6161df2790 100644
--- a/contrib/hstore/hstore_io.c
+++ b/contrib/hstore/hstore_io.c
@@ -1325,7 +1325,7 @@ hstore_to_json_loose(PG_FUNCTION_ARGS)
 	}
 	appendStringInfoChar(&dst, '}');
 
-	PG_RETURN_TEXT_P(cstring_to_text(dst.data));
+	PG_RETURN_TEXT_P(cstring_to_text_with_len(dst.data, dst.len));
 }
 
 PG_FUNCTION_INFO_V1(hstore_to_json);
@@ -1370,7 +1370,7 @@ hstore_to_json(PG_FUNCTION_ARGS)
 	}
 	appendStringInfoChar(&dst, '}');
 
-	PG_RETURN_TEXT_P(cstring_to_text(dst.data));
+	PG_RETURN_TEXT_P(cstring_to_text_with_len(dst.data, dst.len));
 }
 
 PG_FUNCTION_INFO_V1(hstore_to_jsonb);
diff --git a/src/backend/access/brin/brin_minmax_multi.c b/src/backend/access/brin/brin_minmax_multi.c
index a581659fe2..ea326a250b 100644
--- a/src/backend/access/brin/brin_minmax_multi.c
+++ b/src/backend/access/brin/brin_minmax_multi.c
@@ -3063,7 +3063,7 @@ brin_minmax_multi_summary_out(PG_FUNCTION_ARGS)
 
 		appendStringInfo(&str, "%s ... %s", a, b);
 
-		c = cstring_to_text(str.data);
+		c = cstring_to_text_with_len(str.data, str.len);
 
 		astate_values = accumArrayResult(astate_values,
 										 PointerGetDatum(c),
@@ -3095,15 +3095,9 @@ brin_minmax_multi_summary_out(PG_FUNCTION_ARGS)
 	{
 		Datum		a;
 		text	   *b;
-		StringInfoData str;
-
-		initStringInfo(&str);
 
 		a = FunctionCall1(&fmgrinfo, ranges_deserialized->values[idx++]);
-
-		appendStringInfoString(&str, DatumGetCString(a));
-
-		b = cstring_to_text(str.data);
+		b = cstring_to_text(DatumGetCString(a));
 
 		astate_values = accumArrayResult(astate_values,
 										 PointerGetDatum(b),
diff --git a/src/backend/replication/logical/tablesync.c b/src/backend/replication/logical/tablesync.c
index 91ba49a14b..78abbb8196 100644
--- a/src/backend/replication/logical/tablesync.c
+++ b/src/backend/replication/logical/tablesync.c
@@ -1062,7 +1062,7 @@ copy_table(Relation rel)
 			appendStringInfoString(&cmd, quote_identifier(lrel.attnames[i]));
 		}
 
-		appendStringInfo(&cmd, ") TO STDOUT");
+		appendStringInfoString(&cmd, ") TO STDOUT");
 	}
 	else
 	{
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index 081dfa2450..a2bdde0459 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -96,7 +96,7 @@ anytime_typmodout(bool istz, int32 typmod)
 	if (typmod >= 0)
 		return psprintf("(%d)%s", (int) typmod, tz);
 	else
-		return psprintf("%s", tz);
+		return pstrdup(tz);
 }
 
 
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 6594a9aac7..2b7b1b0c0f 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -1453,7 +1453,7 @@ pg_get_indexdef_worker(Oid indexrelid, int colno,
 		appendStringInfoChar(&buf, ')');
 
 		if (idxrec->indnullsnotdistinct)
-			appendStringInfo(&buf, " NULLS NOT DISTINCT");
+			appendStringInfoString(&buf, " NULLS NOT DISTINCT");
 
 		/*
 		 * If it has options, append "WITH (options)"
@@ -2332,9 +2332,9 @@ pg_get_constraintdef_worker(Oid constraintId, bool fullCommand,
 									  Anum_pg_constraint_confdelsetcols, &isnull);
 				if (!isnull)
 				{
-					appendStringInfo(&buf, " (");
+					appendStringInfoString(&buf, " (");
 					decompile_column_index_array(val, conForm->conrelid, &buf);
-					appendStringInfo(&buf, ")");
+					appendStringInfoChar(&buf, ')');
 				}
 
 				break;
@@ -2363,7 +2363,7 @@ pg_get_constraintdef_worker(Oid constraintId, bool fullCommand,
 					((Form_pg_index) GETSTRUCT(indtup))->indnullsnotdistinct)
 					appendStringInfoString(&buf, "NULLS NOT DISTINCT ");
 
-				appendStringInfoString(&buf, "(");
+				appendStringInfoChar(&buf, '(');
 
 				/* Fetch and build target column list */
 				val = SysCacheGetAttr(CONSTROID, tup,
@@ -3583,7 +3583,7 @@ pg_get_function_sqlbody(PG_FUNCTION_ARGS)
 
 	ReleaseSysCache(proctup);
 
-	PG_RETURN_TEXT_P(cstring_to_text(buf.data));
+	PG_RETURN_TEXT_P(cstring_to_text_with_len(buf.data, buf.len));
 }
 
 
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 49cdb290ac..021b760f4e 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -131,7 +131,7 @@ anytimestamp_typmodout(bool istz, int32 typmod)
 	if (typmod >= 0)
 		return psprintf("(%d)%s", (int) typmod, tz);
 	else
-		return psprintf("%s", tz);
+		return pstrdup(tz);
 }
 
 
diff --git a/src/bin/pg_amcheck/pg_amcheck.c b/src/bin/pg_amcheck/pg_amcheck.c
index 3cff319f02..0356e132db 100644
--- a/src/bin/pg_amcheck/pg_amcheck.c
+++ b/src/bin/pg_amcheck/pg_amcheck.c
@@ -1509,7 +1509,7 @@ append_db_pattern_cte(PQExpBuffer buf, const PatternInfoArray *pia,
 			have_values = true;
 			appendPQExpBuffer(buf, "%s\n(%d, ", comma, pattern_id);
 			appendStringLiteralConn(buf, info->db_regex, conn);
-			appendPQExpBufferStr(buf, ")");
+			appendPQExpBufferChar(buf, ')');
 			comma = ",";
 		}
 	}
@@ -1765,7 +1765,7 @@ append_rel_pattern_raw_cte(PQExpBuffer buf, const PatternInfoArray *pia,
 			appendPQExpBufferStr(buf, ", true::BOOLEAN");
 		else
 			appendPQExpBufferStr(buf, ", false::BOOLEAN");
-		appendPQExpBufferStr(buf, ")");
+		appendPQExpBufferChar(buf, ')');
 		comma = ",";
 	}
 
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index d25709ad5f..f4c8b028f9 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -4045,7 +4045,7 @@ dumpPublication(Archive *fout, const PublicationInfo *pubinfo)
 		first = false;
 	}
 
-	appendPQExpBufferStr(query, "'");
+	appendPQExpBufferChar(query, '\'');
 
 	if (pubinfo->pubviaroot)
 		appendPQExpBufferStr(query, ", publish_via_partition_root = true");
@@ -15491,7 +15491,7 @@ dumpTableSchema(Archive *fout, const TableInfo *tbinfo)
 					appendStringLiteralAH(q, qualrelname, fout);
 					appendPQExpBufferStr(q, "::pg_catalog.regclass,");
 					appendStringLiteralAH(q, tbinfo->attnames[j], fout);
-					appendPQExpBufferStr(q, ",");
+					appendPQExpBufferChar(q, ',');
 					appendStringLiteralAH(q, tbinfo->attmissingval[j], fout);
 					appendPQExpBufferStr(q, ");\n\n");
 				}
@@ -16361,8 +16361,8 @@ dumpConstraint(Archive *fout, const ConstraintInfo *coninfo)
 		}
 		else
 		{
-			appendPQExpBuffer(q, "%s",
-							  coninfo->contype == 'p' ? "PRIMARY KEY" : "UNIQUE");
+			appendPQExpBufferStr(q,
+								 coninfo->contype == 'p' ? "PRIMARY KEY" : "UNIQUE");
 			if (indxinfo->indnullsnotdistinct)
 				appendPQExpBuffer(q, " NULLS NOT DISTINCT");
 			appendPQExpBuffer(q, " (");
diff --git a/src/bin/pgbench/pgbench.c b/src/bin/pgbench/pgbench.c
index 9aadcaad71..c749349468 100644
--- a/src/bin/pgbench/pgbench.c
+++ b/src/bin/pgbench/pgbench.c
@@ -3512,8 +3512,7 @@ printVerboseErrorMessages(CState *st, pg_time_usec_t *now, bool is_retry)
 		resetPQExpBuffer(buf);
 
 	printfPQExpBuffer(buf, "client %d ", st->id);
-	appendPQExpBuffer(buf, "%s",
-					  (is_retry ?
+	appendPQExpBufferStr(buf, (is_retry ?
 					   "repeats the transaction after the error" :
 					   "ends the failed transaction"));
 	appendPQExpBuffer(buf, " (try %u", st->tries);
diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c
index 61188d96f2..a141146e70 100644
--- a/src/bin/psql/command.c
+++ b/src/bin/psql/command.c
@@ -4889,9 +4889,9 @@ pset_value_string(const char *param, printQueryOpt *popt)
 	else if (strcmp(param, "footer") == 0)
 		return pstrdup(pset_bool_string(popt->topt.default_footer));
 	else if (strcmp(param, "format") == 0)
-		return psprintf("%s", _align2string(popt->topt.format));
+		return pstrdup(_align2string(popt->topt.format));
 	else if (strcmp(param, "linestyle") == 0)
-		return psprintf("%s", get_line_style(&popt->topt)->name);
+		return pstrdup(get_line_style(&popt->topt)->name);
 	else if (strcmp(param, "null") == 0)
 		return pset_quoted_string(popt->nullPrint
 								  ? popt->nullPrint