s3

Author: krlmlr

R/aaa-auto.R

@@ -2968,7 +2968,9 @@ topological_sorting_impl <- function(
     graph,
     mode
   )
-
+  if (igraph_opt("return.vs.es")) {
+    res <- create_vs(graph, res)
+  }
   res
 }
 

R/structural-properties.R

@@ -2305,18 +2305,12 @@ coreness <- function(graph, mode = c("all", "out", "in")) {
 #' topo_sort(g)
 #'
 topo_sort <- function(graph, mode = c("out", "all", "in")) {
-  ensure_igraph(graph)
   mode <- igraph_match_arg(mode)
-  mode <- switch(mode, "out" = 1, "in" = 2, "all" = 3)
-
-  on.exit(.Call(R_igraph_finalizer))
-  res <- .Call(Rx_igraph_topological_sorting, graph, as.numeric(mode)) + 1L
-
-  if (igraph_opt("return.vs.es")) {
-    res <- create_vs(graph, res)
-  }
 
-  res
+  topological_sorting_impl(
+    graph = graph,
+    mode = mode
+  )
 }
 
 #' Finding a feedback arc set in a graph

patch/0102-Return-value-of-igraph_topological_sorting-is-a-vect.patch

@@ -0,0 +1,27 @@
+From 487e971253fec664a9b7e49e3162efac8f4ec654 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Kirill=20M=C3=BCller?= <[email protected]>
+Date: Sun, 2 Nov 2025 15:44:27 +0100
+Subject: [PATCH] Return value of igraph_topological_sorting() is a vector of
+ vertices
+
+---
+ src/vendor/cigraph/interfaces/functions.yaml | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+diff --git a/src/vendor/cigraph/interfaces/functions.yaml b/src/vendor/cigraph/interfaces/functions.yaml
+index 6ef2506aff..6a4590b36f 100644
+--- a/src/vendor/cigraph/interfaces/functions.yaml
++++ b/src/vendor/cigraph/interfaces/functions.yaml
+@@ -847,7 +847,8 @@ igraph_neighborhood_graphs:
+     DEPS: vids ON graph
+ 
+ igraph_topological_sorting:
+-    PARAMS: GRAPH graph, OUT VECTOR_INT res, NEIMODE mode=OUT
++    PARAMS: GRAPH graph, OUT VERTEX_INDICES res, NEIMODE mode=OUT
++    DEPS: res ON graph
+ 
+ igraph_feedback_arc_set:
+     # Default algorithm is the approximate method because it is faster and the
+-- 
+2.50.1
+

src/rinterface.c

@@ -4115,7 +4115,7 @@ SEXP R_igraph_topological_sorting(SEXP graph, SEXP mode) {
   IGRAPH_R_CHECK(igraph_topological_sorting(&c_graph, &c_res, c_mode));
 
                                         /* Convert output */
-  PROTECT(res=R_igraph_vector_int_to_SEXP(&c_res));
+  PROTECT(res=R_igraph_vector_int_to_SEXPp1(&c_res));
   igraph_vector_int_destroy(&c_res);
   IGRAPH_FINALLY_CLEAN(1);
   r_result = res;

src/vendor/cigraph/interfaces/functions.yaml

@@ -847,7 +847,8 @@ igraph_neighborhood_graphs:
     DEPS: vids ON graph
 
 igraph_topological_sorting:
-    PARAMS: GRAPH graph, OUT VECTOR_INT res, NEIMODE mode=OUT
+    PARAMS: GRAPH graph, OUT VERTEX_INDICES res, NEIMODE mode=OUT
+    DEPS: res ON graph
 
 igraph_feedback_arc_set:
     # Default algorithm is the approximate method because it is faster and the