Fix: Drag link search doesn't always connect to socket

Connecting to some sockets of a few nodes via the drag link search
would fail and trigger an assert, because the picked socket wasn't
available. This was due to some sockets only being available with
certain settings.

This patch fixes these cases by adding the availability conditions of
the socket to the node declaration with the `make_available` method
or manually adding a `node_link_gather_search` function.

Differential Revision: https://developer.blender.org/D14283

1 files changed, 21 insertions, 0 deletions

diff --git a/source/blender/nodes/shader/nodes/node_shader_tex_sky.cc b/source/blender/nodes/shader/nodes/node_shader_tex_sky.cc
index d4a0c092acd..a5ab6db0002 100644
--- a/source/blender/nodes/shader/nodes/node_shader_tex_sky.cc
+++ b/source/blender/nodes/shader/nodes/node_shader_tex_sky.cc
@@ -10,6 +10,8 @@
 #include "UI_interface.h"
 #include "UI_resources.h"
 
+#include "NOD_socket_search_link.hh"
+
 namespace blender::nodes::node_shader_tex_sky_cc {
 
 static void node_declare(NodeDeclarationBuilder &b)
@@ -229,6 +231,24 @@ static void node_shader_update_sky(bNodeTree *ntree, bNode *node)
   nodeSetSocketAvailability(ntree, sockVector, !(tex->sky_model == 2 && tex->sun_disc == 1));
 }
 
+static void node_gather_link_searches(GatherLinkSearchOpParams &params)
+{
+  const NodeDeclaration &declaration = *params.node_type().fixed_declaration;
+  if (params.in_out() == SOCK_OUT) {
+    search_link_ops_for_declarations(params, declaration.outputs());
+    return;
+  }
+  if (params.node_tree().typeinfo->validate_link(
+               static_cast<eNodeSocketDatatype>(params.other_socket().type), SOCK_FLOAT)) {
+    params.add_item(IFACE_("Vector"), [](LinkSearchOpParams &params) {
+      bNode &node = params.add_node("ShaderNodeTexSky");
+      NodeTexSky *tex = (NodeTexSky *)node.storage;
+      tex->sun_disc = false;
+      params.update_and_connect_available_socket(node, "Vector");
+    });
+  }
+}
+
 }  // namespace blender::nodes::node_shader_tex_sky_cc
 
 /* node type definition */
@@ -247,6 +267,7 @@ void register_node_type_sh_tex_sky()
   node_type_gpu(&ntype, file_ns::node_shader_gpu_tex_sky);
   /* Remove vector input for Nishita sky model. */
   node_type_update(&ntype, file_ns::node_shader_update_sky);
+  ntype.gather_link_search_ops = file_ns::node_gather_link_searches;
 
   nodeRegisterType(&ntype);
 }