From 4dba0113fdfd325b54955b799f041b662cd50dd6 Mon Sep 17 00:00:00 2001
From: Campbell Barton <campbell@blender.org>
Date: Wed, 18 Jun 2025 04:42:42 +0000
Subject: [PATCH] Fix #140396: bmesh.ops.dissolve_edges fails to dissolve
 vertices

Add an optional init function which operators

An alternative to [0] which missed Python API support (causing #140451).
While that could be resolved, tracking which "slots" have been set
would have to be flagged on every map/hash insertion which seems
excessive and is prone to bmesh operators failing if the flag is ever
missed. Prefer a simpler init function so dissolve edges doesn't have
a zero threshold.

Also support multi-line comment blocks in the generated API docs.

[0]: bd3a66a4167284aa2f215147f4128fcc26e307dc
---
 doc/python_api/rst_from_bmesh_opdefines.py    |  38 ++-
 .../blender/bmesh/intern/bmesh_opdefines.cc   | 243 ++++++++++++------
 .../bmesh/intern/bmesh_operator_api.hh        |   5 +
 .../blender/bmesh/intern/bmesh_operators.cc   |   4 +
 .../bmesh/intern/bmesh_operators_private.hh   |   1 +
 .../blender/bmesh/operators/bmo_dissolve.cc   |   6 +
 6 files changed, 202 insertions(+), 95 deletions(-)

diff --git a/doc/python_api/rst_from_bmesh_opdefines.py b/doc/python_api/rst_from_bmesh_opdefines.py
index faf7cd900b9..c634b140a3d 100644
--- a/doc/python_api/rst_from_bmesh_opdefines.py
+++ b/doc/python_api/rst_from_bmesh_opdefines.py
@@ -16,6 +16,7 @@
 
 import os
 import re
+import textwrap
 
 CURRENT_DIR = os.path.abspath(os.path.dirname(__file__))
 SOURCE_DIR = os.path.normpath(os.path.abspath(os.path.normpath(os.path.join(CURRENT_DIR, "..", ".."))))
@@ -163,20 +164,22 @@ def main():
             l = l.replace("{", "(")
             l = l.replace("}", ")")
 
-            if l.startswith("/*"):
-                l = l.replace("/*", "'''own <")
-            else:
-                # NOTE: `inline <...>` aren't used anymore, all doc-string comments require their own line.
-                l = l.replace("/*", "'''inline <")
-            l = l.replace("*/", ">''',")
-
-            # exec func. eg: bmo_rotate_edges_exec,
-            if l.startswith("bmo_") and l.endswith("_exec,"):
+            # Skip `exec` & `init` functions. eg: `/*exec*/ bmo_rotate_edges_exec`,
+            if l.startswith("/*exec*/ "):
                 l = "None,"
+            elif l.startswith("/*init*/ "):
+                l = "None,"
+            else:
+                if l.startswith("/*"):
+                    l = l.replace("/*", "'''own <")
+                else:
+                    # NOTE: `inline <...>` aren't used anymore, all doc-string comments require their own line.
+                    l = l.replace("/*", "'''inline <")
+                l = l.replace("*/", ">''',")
 
-            # enums
-            if l.startswith("static BMO_FlagSet "):
-                is_enum = True
+                # enums
+                if l.startswith("static BMO_FlagSet "):
+                    is_enum = True
 
             b[i] = l
 
@@ -263,6 +266,12 @@ def main():
                     if type(args[i - 1]) == str:
                         if args[i - 1].startswith("own <"):
                             comment = args[i - 1][5:-1].strip()  # strip `our <...>`
+                            if "\n" in comment:
+                                # Remove leading "*" of comment blocks.
+                                comment = "\n".join([
+                                    "" if l.strip() == "*" else l.lstrip().removeprefix("* ")
+                                    for l in comment.split("\n")
+                                ])
                     else:
                         comment = ""
 
@@ -397,7 +406,8 @@ def main():
             if comment == "":
                 comment = "Undocumented."
 
-            fw("   :arg {:s}: {:s}\n".format(name, comment))
+            # Indent a block to support multiple lines.
+            fw("   :arg {:s}:\n{:s}\n".format(name, textwrap.indent(comment, "      ")))
             fw("   :type {:s}: {:s}\n".format(name, tp))
 
         if args_out_wash:
@@ -406,7 +416,7 @@ def main():
             for (name, _, tp, comment) in args_out_wash:
                 assert name.endswith(".out")
                 name = name[:-4]
-                fw("      - ``{:s}``: {:s}\n\n".format(name, comment))
+                fw("      - ``{:s}``:\n{:s}\n\n".format(name, textwrap.indent(comment, "        ")))
                 fw("        **type** {:s}\n".format(tp))
 
             fw("\n")
diff --git a/source/blender/bmesh/intern/bmesh_opdefines.cc b/source/blender/bmesh/intern/bmesh_opdefines.cc
index aa09761bea5..5e703f3e226 100644
--- a/source/blender/bmesh/intern/bmesh_opdefines.cc
+++ b/source/blender/bmesh/intern/bmesh_opdefines.cc
@@ -166,7 +166,8 @@ static BMOpDefine bmo_smooth_vert_def = {
     },
     /*slot_types_out*/
     {{{'\0'}}},
-    bmo_smooth_vert_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_smooth_vert_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC),
 };
 
@@ -198,7 +199,8 @@ static BMOpDefine bmo_smooth_laplacian_vert_def = {
     },
     /*slot_types_out*/
     {{{'\0'}}},
-    bmo_smooth_laplacian_vert_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_smooth_laplacian_vert_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC),
 };
 
@@ -217,7 +219,8 @@ static BMOpDefine bmo_recalc_face_normals_def = {
     },
     /*slot_types_out*/
     {{{'\0'}}},
-    bmo_recalc_face_normals_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_recalc_face_normals_exec,
     (BMO_OPTYPE_FLAG_UNTAN_MULTIRES | BMO_OPTYPE_FLAG_NORMALS_CALC),
 };
 
@@ -244,7 +247,8 @@ static BMOpDefine bmo_planar_faces_def = {
         {"geom.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_VERT | BM_EDGE | BM_FACE}},
         {{'\0'}},
     },
-    bmo_planar_faces_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_planar_faces_exec,
     (BMO_OPTYPE_FLAG_SELECT_FLUSH | BMO_OPTYPE_FLAG_SELECT_VALIDATE),
 };
 
@@ -278,7 +282,8 @@ static BMOpDefine bmo_region_extend_def = {
         {"geom.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_VERT | BM_EDGE | BM_FACE}},
         {{'\0'}},
     },
-    bmo_region_extend_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_region_extend_exec,
     (BMO_OPTYPE_FLAG_SELECT_FLUSH | BMO_OPTYPE_FLAG_SELECT_VALIDATE),
 };
 
@@ -304,7 +309,8 @@ static BMOpDefine bmo_rotate_edges_def = {
         {"edges.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_EDGE}},
         {{'\0'}},
     },
-    bmo_rotate_edges_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_rotate_edges_exec,
     (BMO_OPTYPE_FLAG_UNTAN_MULTIRES | BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH |
      BMO_OPTYPE_FLAG_SELECT_VALIDATE),
 };
@@ -327,7 +333,8 @@ static BMOpDefine bmo_reverse_faces_def = {
     },
     /*slot_types_out*/
     {{{'\0'}}},
-    bmo_reverse_faces_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_reverse_faces_exec,
     (BMO_OPTYPE_FLAG_UNTAN_MULTIRES | BMO_OPTYPE_FLAG_NORMALS_CALC),
 };
 
@@ -346,7 +353,8 @@ static BMOpDefine bmo_flip_quad_tessellation_def = {
     },
     /*slot_types_out*/
     {{{'\0'}}},
-    bmo_flip_quad_tessellation_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_flip_quad_tessellation_exec,
     (BMO_OPTYPE_FLAG_UNTAN_MULTIRES | BMO_OPTYPE_FLAG_NORMALS_CALC),
 };
 
@@ -375,7 +383,8 @@ static BMOpDefine bmo_bisect_edges_def = {
         {"geom_split.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_VERT | BM_EDGE | BM_FACE}},
         {{'\0'}},
     },
-    bmo_bisect_edges_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_bisect_edges_exec,
     (BMO_OPTYPE_FLAG_UNTAN_MULTIRES | BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH |
      BMO_OPTYPE_FLAG_SELECT_VALIDATE),
 };
@@ -418,7 +427,8 @@ static BMOpDefine bmo_mirror_def = {
         {"geom.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_VERT | BM_EDGE | BM_FACE}},
         {{'\0'}},
     },
-    bmo_mirror_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_mirror_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH |
      BMO_OPTYPE_FLAG_SELECT_VALIDATE),
 };
@@ -451,7 +461,8 @@ static BMOpDefine bmo_find_doubles_def = {
          {eBMOpSlotSubType_Elem(BMO_OP_SLOT_SUBTYPE_MAP_ELEM)}},
         {{'\0'}},
     },
-    bmo_find_doubles_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_find_doubles_exec,
     (BMO_OPTYPE_FLAG_NOP),
 };
 
@@ -474,7 +485,8 @@ static BMOpDefine bmo_remove_doubles_def = {
     },
     /*slot_types_out*/
     {{{'\0'}}},
-    bmo_remove_doubles_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_remove_doubles_exec,
     (BMO_OPTYPE_FLAG_UNTAN_MULTIRES | BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH |
      BMO_OPTYPE_FLAG_SELECT_VALIDATE),
 };
@@ -496,7 +508,8 @@ static BMOpDefine bmo_collapse_def = {
     },
     /*slot_types_out*/
     {{{'\0'}}},
-    bmo_collapse_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_collapse_exec,
     (BMO_OPTYPE_FLAG_UNTAN_MULTIRES | BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH |
      BMO_OPTYPE_FLAG_SELECT_VALIDATE),
 };
@@ -518,7 +531,8 @@ static BMOpDefine bmo_pointmerge_facedata_def = {
     },
     /*slot_types_out*/
     {{{'\0'}}},
-    bmo_pointmerge_facedata_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_pointmerge_facedata_exec,
     (BMO_OPTYPE_FLAG_NOP),
 };
 
@@ -539,7 +553,8 @@ static BMOpDefine bmo_average_vert_facedata_def = {
     },
     /*slot_types_out*/
     {{{'\0'}}},
-    bmo_average_vert_facedata_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_average_vert_facedata_exec,
     (BMO_OPTYPE_FLAG_NOP),
 };
 
@@ -560,7 +575,8 @@ static BMOpDefine bmo_pointmerge_def = {
     },
     /*slot_types_out*/
     {{{'\0'}}},
-    bmo_pointmerge_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_pointmerge_exec,
     (BMO_OPTYPE_FLAG_UNTAN_MULTIRES | BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH |
      BMO_OPTYPE_FLAG_SELECT_VALIDATE),
 };
@@ -580,7 +596,8 @@ static BMOpDefine bmo_collapse_uvs_def = {
     },
     /*slot_types_out*/
     {{{'\0'}}},
-    bmo_collapse_uvs_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_collapse_uvs_exec,
     (BMO_OPTYPE_FLAG_NOP),
 };
 
@@ -601,7 +618,8 @@ static BMOpDefine bmo_weld_verts_def = {
     },
     /*slot_types_out*/
     {{{'\0'}}},
-    bmo_weld_verts_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_weld_verts_exec,
     (BMO_OPTYPE_FLAG_UNTAN_MULTIRES | BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH |
      BMO_OPTYPE_FLAG_SELECT_VALIDATE),
 };
@@ -626,7 +644,8 @@ static BMOpDefine bmo_create_vert_def = {
         {"vert.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_VERT}},
         {{'\0'}},
     },
-    bmo_create_vert_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_create_vert_exec,
     (BMO_OPTYPE_FLAG_NOP),
 };
 
@@ -673,7 +692,8 @@ static BMOpDefine bmo_join_triangles_def = {
         {"faces.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_FACE}},
         {{'\0'}},
     },
-    bmo_join_triangles_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_join_triangles_exec,
     (BMO_OPTYPE_FLAG_UNTAN_MULTIRES | BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH |
      BMO_OPTYPE_FLAG_SELECT_VALIDATE),
 };
@@ -712,7 +732,8 @@ static BMOpDefine bmo_contextual_create_def = {
         {"edges.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_EDGE}},
         {{'\0'}},
     },
-    bmo_contextual_create_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_contextual_create_exec,
     (BMO_OPTYPE_FLAG_UNTAN_MULTIRES | BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH |
      BMO_OPTYPE_FLAG_SELECT_VALIDATE),
 };
@@ -744,7 +765,8 @@ static BMOpDefine bmo_bridge_loops_def = {
         {"edges.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_EDGE}},
         {{'\0'}},
     },
-    bmo_bridge_loops_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_bridge_loops_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH |
      BMO_OPTYPE_FLAG_SELECT_VALIDATE),
 };
@@ -778,7 +800,8 @@ static BMOpDefine bmo_grid_fill_def = {
         {"faces.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_FACE}},
         {{'\0'}},
     },
-    bmo_grid_fill_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_grid_fill_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH),
 };
 
@@ -803,7 +826,8 @@ static BMOpDefine bmo_holes_fill_def = {
         {"faces.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_FACE}},
         {{'\0'}},
     },
-    bmo_holes_fill_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_holes_fill_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH),
 };
 
@@ -830,7 +854,8 @@ static BMOpDefine bmo_face_attribute_fill_def = {
         {"faces_fail.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_FACE}},
         {{'\0'}},
     },
-    bmo_face_attribute_fill_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_face_attribute_fill_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC),
 };
 
@@ -860,7 +885,8 @@ static BMOpDefine bmo_edgeloop_fill_def = {
         {"faces.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_FACE}},
         {{'\0'}},
     },
-    bmo_edgeloop_fill_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_edgeloop_fill_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH),
 };
 
@@ -889,7 +915,8 @@ static BMOpDefine bmo_edgenet_fill_def = {
         {"faces.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_FACE}},
         {{'\0'}},
     },
-    bmo_edgenet_fill_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_edgenet_fill_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH),
 };
 
@@ -917,7 +944,8 @@ static BMOpDefine bmo_edgenet_prepare_def = {
         {"edges.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_EDGE}},
         {{'\0'}},
     },
-    bmo_edgenet_prepare_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_edgenet_prepare_exec,
     (BMO_OPTYPE_FLAG_NOP),
 };
 
@@ -944,7 +972,8 @@ static BMOpDefine bmo_rotate_def = {
     },
     /*slot_types_out*/
     {{{'\0'}}},
-    bmo_rotate_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_rotate_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC),
 };
 
@@ -969,7 +998,8 @@ static BMOpDefine bmo_translate_def = {
     },
     /*slot_types_out*/
     {{{'\0'}}},
-    bmo_translate_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_translate_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC),
 };
 
@@ -994,7 +1024,8 @@ static BMOpDefine bmo_scale_def = {
     },
     /*slot_types_out*/
     {{{'\0'}}},
-    bmo_scale_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_scale_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC),
 };
 
@@ -1020,7 +1051,8 @@ static BMOpDefine bmo_transform_def = {
     },
     /*slot_types_out*/
     {{{'\0'}}},
-    bmo_transform_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_transform_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC),
 };
 
@@ -1043,7 +1075,8 @@ static BMOpDefine bmo_object_load_bmesh_def = {
     },
     /*slot_types_out*/
     {{{'\0'}}},
-    bmo_object_load_bmesh_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_object_load_bmesh_exec,
     (BMO_OPTYPE_FLAG_NOP),
 };
 
@@ -1065,7 +1098,8 @@ static BMOpDefine bmo_bmesh_to_mesh_def = {
     },
     /*slot_types_out*/
     {{{'\0'}}},
-    bmo_bmesh_to_mesh_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_bmesh_to_mesh_exec,
     (BMO_OPTYPE_FLAG_NOP),
 };
 
@@ -1089,7 +1123,8 @@ static BMOpDefine bmo_mesh_to_bmesh_def = {
     },
     /*slot_types_out*/
     {{{'\0'}}},
-    bmo_mesh_to_bmesh_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_mesh_to_bmesh_exec,
     (BMO_OPTYPE_FLAG_NOP),
 };
 
@@ -1116,7 +1151,8 @@ static BMOpDefine bmo_extrude_discrete_faces_def = {
         {"faces.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_FACE}},
         {{'\0'}},
     },
-    bmo_extrude_discrete_faces_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_extrude_discrete_faces_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC),
 };
 
@@ -1144,7 +1180,8 @@ static BMOpDefine bmo_extrude_edge_only_def = {
         {"geom.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_VERT | BM_EDGE | BM_FACE}},
         {{'\0'}},
     },
-    bmo_extrude_edge_only_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_extrude_edge_only_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC),
 };
 
@@ -1171,7 +1208,8 @@ static BMOpDefine bmo_extrude_vert_indiv_def = {
         {"verts.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_VERT}},
         {{'\0'}},
     },
-    bmo_extrude_vert_indiv_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_extrude_vert_indiv_exec,
     (BMO_OPTYPE_FLAG_SELECT_FLUSH),
 };
 
@@ -1197,7 +1235,8 @@ static BMOpDefine bmo_connect_verts_def = {
         {"edges.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_EDGE}},
         {{'\0'}},
     },
-    bmo_connect_verts_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_connect_verts_exec,
     (BMO_OPTYPE_FLAG_UNTAN_MULTIRES | BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH),
 };
 
@@ -1220,7 +1259,8 @@ static BMOpDefine bmo_connect_verts_concave_def = {
         {"faces.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_FACE}},
         {{'\0'}},
     },
-    bmo_connect_verts_concave_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_connect_verts_concave_exec,
     (BMO_OPTYPE_FLAG_UNTAN_MULTIRES | BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH),
 };
 
@@ -1245,7 +1285,8 @@ static BMOpDefine bmo_connect_verts_nonplanar_def = {
         {"faces.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_FACE}},
         {{'\0'}},
     },
-    bmo_connect_verts_nonplanar_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_connect_verts_nonplanar_exec,
     (BMO_OPTYPE_FLAG_UNTAN_MULTIRES | BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH),
 };
 
@@ -1271,7 +1312,8 @@ static BMOpDefine bmo_connect_vert_pair_def = {
         {"edges.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_EDGE}},
         {{'\0'}},
     },
-    bmo_connect_vert_pair_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_connect_vert_pair_exec,
     (BMO_OPTYPE_FLAG_UNTAN_MULTIRES | BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH),
 };
 
@@ -1305,7 +1347,8 @@ static BMOpDefine bmo_extrude_face_region_def = {
         {"geom.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_VERT | BM_EDGE | BM_FACE}},
         {{'\0'}},
     },
-    bmo_extrude_face_region_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_extrude_face_region_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC),
 };
 
@@ -1326,7 +1369,8 @@ static BMOpDefine bmo_dissolve_verts_def = {
     },
     /*slot_types_out*/
     {{{'\0'}}},
-    bmo_dissolve_verts_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_dissolve_verts_exec,
     (BMO_OPTYPE_FLAG_UNTAN_MULTIRES | BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH |
      BMO_OPTYPE_FLAG_SELECT_VALIDATE),
 };
@@ -1344,7 +1388,8 @@ static BMOpDefine bmo_dissolve_edges_def = {
         {"use_verts", BMO_OP_SLOT_BOOL},
         /* Split off face corners to maintain surrounding geometry. */
         {"use_face_split", BMO_OP_SLOT_BOOL},
-        /* Do not dissolve verts between 2 edges when their angle exceeds this threshold. */
+        /* Do not dissolve verts between 2 edges when their angle exceeds this threshold.
+         * Disabled by default. */
         {"angle_threshold", BMO_OP_SLOT_FLT},
         {{'\0'}},
     },
@@ -1353,7 +1398,8 @@ static BMOpDefine bmo_dissolve_edges_def = {
         {"region.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_FACE}},
         {{'\0'}},
     },
-    bmo_dissolve_edges_exec,
+    /*init*/ bmo_dissolve_edges_init,
+    /*exec*/ bmo_dissolve_edges_exec,
     (BMO_OPTYPE_FLAG_UNTAN_MULTIRES | BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH |
      BMO_OPTYPE_FLAG_SELECT_VALIDATE),
 };
@@ -1376,7 +1422,8 @@ static BMOpDefine bmo_dissolve_faces_def = {
         {"region.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_FACE}},
         {{'\0'}},
     },
-    bmo_dissolve_faces_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_dissolve_faces_exec,
     (BMO_OPTYPE_FLAG_UNTAN_MULTIRES | BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH |
      BMO_OPTYPE_FLAG_SELECT_VALIDATE),
 };
@@ -1419,7 +1466,8 @@ static BMOpDefine bmo_dissolve_limit_def = {
         {"region.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_FACE}},
         {{'\0'}},
     },
-    bmo_dissolve_limit_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_dissolve_limit_exec,
     (BMO_OPTYPE_FLAG_UNTAN_MULTIRES | BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH |
      BMO_OPTYPE_FLAG_SELECT_VALIDATE),
 };
@@ -1441,7 +1489,8 @@ static BMOpDefine bmo_dissolve_degenerate_def = {
     },
     /*slot_types_out*/
     {{{'\0'}}},
-    bmo_dissolve_degenerate_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_dissolve_degenerate_exec,
     (BMO_OPTYPE_FLAG_UNTAN_MULTIRES | BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH |
      BMO_OPTYPE_FLAG_SELECT_VALIDATE),
 };
@@ -1495,7 +1544,8 @@ static BMOpDefine bmo_triangulate_def = {
          {eBMOpSlotSubType_Elem(BMO_OP_SLOT_SUBTYPE_MAP_ELEM)}},
         {{'\0'}},
     },
-    bmo_triangulate_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_triangulate_exec,
     (BMO_OPTYPE_FLAG_UNTAN_MULTIRES | BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH),
 };
 
@@ -1516,7 +1566,8 @@ static BMOpDefine bmo_unsubdivide_def = {
     },
     /*slot_types_out*/
     {{{'\0'}}},
-    bmo_unsubdivide_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_unsubdivide_exec,
     (BMO_OPTYPE_FLAG_UNTAN_MULTIRES | BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH |
      BMO_OPTYPE_FLAG_SELECT_VALIDATE),
 };
@@ -1587,7 +1638,8 @@ static BMOpDefine bmo_subdivide_edges_def = {
         {"geom.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_VERT | BM_EDGE | BM_FACE}},
         {{'\0'}},
     },
-    bmo_subdivide_edges_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_subdivide_edges_exec,
     (BMO_OPTYPE_FLAG_UNTAN_MULTIRES | BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH |
      BMO_OPTYPE_FLAG_SELECT_VALIDATE),
 };
@@ -1634,7 +1686,8 @@ static BMOpDefine bmo_subdivide_edgering_def = {
         {"faces.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_FACE}},
         {{'\0'}},
     },
-    bmo_subdivide_edgering_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_subdivide_edgering_exec,
     (BMO_OPTYPE_FLAG_UNTAN_MULTIRES | BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH |
      BMO_OPTYPE_FLAG_SELECT_VALIDATE),
 };
@@ -1672,7 +1725,8 @@ static BMOpDefine bmo_bisect_plane_def = {
         {"geom.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_VERT | BM_EDGE | BM_FACE}},
         {{'\0'}},
     },
-    bmo_bisect_plane_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_bisect_plane_exec,
     (BMO_OPTYPE_FLAG_UNTAN_MULTIRES | BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH |
      BMO_OPTYPE_FLAG_SELECT_VALIDATE),
 };
@@ -1708,7 +1762,8 @@ static BMOpDefine bmo_delete_def = {
     },
     /*slot_types_out*/
     {{{'\0'}}},
-    bmo_delete_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_delete_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH |
      BMO_OPTYPE_FLAG_SELECT_VALIDATE),
 };
@@ -1756,7 +1811,8 @@ static BMOpDefine bmo_duplicate_def = {
          {eBMOpSlotSubType_Elem(BMO_OP_SLOT_SUBTYPE_MAP_ELEM)}},
         {{'\0'}},
     },
-    bmo_duplicate_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_duplicate_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH),
 };
 
@@ -1789,7 +1845,8 @@ static BMOpDefine bmo_split_def = {
          {eBMOpSlotSubType_Elem(BMO_OP_SLOT_SUBTYPE_MAP_ELEM)}},
         {{'\0'}},
     },
-    bmo_split_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_split_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH),
 };
 
@@ -1831,7 +1888,8 @@ static BMOpDefine bmo_spin_def = {
         {"geom_last.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_VERT | BM_EDGE | BM_FACE}},
         {{'\0'}},
     },
-    bmo_spin_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_spin_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH),
 };
 
@@ -1852,7 +1910,8 @@ static BMOpDefine bmo_rotate_uvs_def = {
     },
     /*slot_types_out*/
     {{{'\0'}}},
-    bmo_rotate_uvs_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_rotate_uvs_exec,
     (BMO_OPTYPE_FLAG_NOP),
 };
 
@@ -1871,7 +1930,8 @@ static BMOpDefine bmo_reverse_uvs_def = {
     },
     /*slot_types_out*/
     {{{'\0'}}},
-    bmo_reverse_uvs_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_reverse_uvs_exec,
     (BMO_OPTYPE_FLAG_NOP),
 };
 
@@ -1894,7 +1954,8 @@ static BMOpDefine bmo_rotate_colors_def = {
     },
     /*slot_types_out*/
     {{{'\0'}}},
-    bmo_rotate_colors_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_rotate_colors_exec,
     (BMO_OPTYPE_FLAG_NOP),
 };
 
@@ -1915,7 +1976,8 @@ static BMOpDefine bmo_reverse_colors_def = {
     },
     /*slot_types_out*/
     {{{'\0'}}},
-    bmo_reverse_colors_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_reverse_colors_exec,
     (BMO_OPTYPE_FLAG_NOP),
 };
 
@@ -1946,7 +2008,8 @@ static BMOpDefine bmo_split_edges_def = {
         {"edges.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_EDGE}},
         {{'\0'}},
     },
-    bmo_split_edges_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_split_edges_exec,
     (BMO_OPTYPE_FLAG_UNTAN_MULTIRES | BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH),
 };
 
@@ -1977,7 +2040,8 @@ static BMOpDefine bmo_create_grid_def = {
         {"verts.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_VERT}},
         {{'\0'}},
     },
-    bmo_create_grid_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_create_grid_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH),
 };
 
@@ -2008,7 +2072,8 @@ static BMOpDefine bmo_create_uvsphere_def = {
         {"verts.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_VERT}},
         {{'\0'}},
     },
-    bmo_create_uvsphere_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_create_uvsphere_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH),
 };
 
@@ -2037,7 +2102,8 @@ static BMOpDefine bmo_create_icosphere_def = {
         {"verts.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_VERT}},
         {{'\0'}},
     },
-    bmo_create_icosphere_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_create_icosphere_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH),
 };
 
@@ -2062,7 +2128,8 @@ static BMOpDefine bmo_create_monkey_def = {
         {"verts.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_VERT}},
         {{'\0'}},
     },
-    bmo_create_monkey_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_create_monkey_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH),
 };
 
@@ -2099,7 +2166,8 @@ static BMOpDefine bmo_create_cone_def = {
         {"verts.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_VERT}},
         {{'\0'}},
     },
-    bmo_create_cone_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_create_cone_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH),
 };
 
@@ -2130,7 +2198,8 @@ static BMOpDefine bmo_create_circle_def = {
         {"verts.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_VERT}},
         {{'\0'}},
     },
-    bmo_create_circle_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_create_circle_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH),
 };
 
@@ -2157,7 +2226,8 @@ static BMOpDefine bmo_create_cube_def = {
         {"verts.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_VERT}},
         {{'\0'}},
     },
-    bmo_create_cube_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_create_cube_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH),
 };
 
@@ -2284,7 +2354,8 @@ static BMOpDefine bmo_bevel_def = {
         {{'\0'}},
     },
 
-    bmo_bevel_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_bevel_exec,
     (BMO_OPTYPE_FLAG_UNTAN_MULTIRES | BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH |
      BMO_OPTYPE_FLAG_SELECT_VALIDATE),
 };
@@ -2324,7 +2395,8 @@ static BMOpDefine bmo_beautify_fill_def = {
         {"geom.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_VERT | BM_EDGE | BM_FACE}},
         {{'\0'}},
     },
-    bmo_beautify_fill_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_beautify_fill_exec,
     (BMO_OPTYPE_FLAG_UNTAN_MULTIRES | BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH |
      BMO_OPTYPE_FLAG_SELECT_VALIDATE),
 };
@@ -2354,7 +2426,8 @@ static BMOpDefine bmo_triangle_fill_def = {
         {"geom.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_VERT | BM_EDGE | BM_FACE}},
         {{'\0'}},
     },
-    bmo_triangle_fill_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_triangle_fill_exec,
     (BMO_OPTYPE_FLAG_UNTAN_MULTIRES | BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH),
 };
 
@@ -2378,7 +2451,8 @@ static BMOpDefine bmo_solidify_def = {
         {"geom.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_VERT | BM_EDGE | BM_FACE}},
         {{'\0'}},
     },
-    bmo_solidify_face_region_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_solidify_face_region_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH),
 };
 
@@ -2411,7 +2485,8 @@ static BMOpDefine bmo_inset_individual_def = {
         {"faces.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_FACE}},
         {{'\0'}},
     },
-    bmo_inset_individual_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_inset_individual_exec,
     /* Caller needs to handle BMO_OPTYPE_FLAG_SELECT_FLUSH. */
     (BMO_OPTYPE_FLAG_NORMALS_CALC),
 };
@@ -2453,7 +2528,8 @@ static BMOpDefine bmo_inset_region_def = {
         {"faces.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_FACE}},
         {{'\0'}},
     },
-    bmo_inset_region_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_inset_region_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH),
 };
 
@@ -2478,7 +2554,8 @@ static BMOpDefine bmo_offset_edgeloops_def = {
         {"edges.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_EDGE}},
         {{'\0'}},
     },
-    bmo_offset_edgeloops_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_offset_edgeloops_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH),
 };
 
@@ -2519,7 +2596,8 @@ static BMOpDefine bmo_wireframe_def = {
         {"faces.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_FACE}},
         {{'\0'}},
     },
-    bmo_wireframe_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_wireframe_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH |
      BMO_OPTYPE_FLAG_SELECT_VALIDATE),
 };
@@ -2561,7 +2639,8 @@ static BMOpDefine bmo_poke_def = {
         {"faces.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_FACE}},
         {{'\0'}},
     },
-    bmo_poke_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_poke_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH |
      BMO_OPTYPE_FLAG_SELECT_VALIDATE),
 };
@@ -2600,7 +2679,8 @@ static BMOpDefine bmo_convex_hull_def = {
         {"geom_holes.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_VERT | BM_EDGE | BM_FACE}},
         {{'\0'}},
     },
-    bmo_convex_hull_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_convex_hull_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH |
      BMO_OPTYPE_FLAG_SELECT_VALIDATE),
 };
@@ -2638,7 +2718,8 @@ static BMOpDefine bmo_symmetrize_def = {
         {"geom.out", BMO_OP_SLOT_ELEMENT_BUF, {BM_VERT | BM_EDGE | BM_FACE}},
         {{'\0'}},
     },
-    bmo_symmetrize_exec,
+    /*init*/ nullptr,
+    /*exec*/ bmo_symmetrize_exec,
     (BMO_OPTYPE_FLAG_NORMALS_CALC | BMO_OPTYPE_FLAG_SELECT_FLUSH |
      BMO_OPTYPE_FLAG_SELECT_VALIDATE),
 };
diff --git a/source/blender/bmesh/intern/bmesh_operator_api.hh b/source/blender/bmesh/intern/bmesh_operator_api.hh
index 983cc3e3cfe..428d5411ab4 100644
--- a/source/blender/bmesh/intern/bmesh_operator_api.hh
+++ b/source/blender/bmesh/intern/bmesh_operator_api.hh
@@ -327,6 +327,11 @@ struct BMOpDefine {
   const char *opname;
   BMOSlotType slot_types_in[BMO_OP_MAX_SLOTS];
   BMOSlotType slot_types_out[BMO_OP_MAX_SLOTS];
+  /**
+   * Optional initialize function.
+   * Can be used for setting defaults.
+   */
+  void (*init)(BMOperator *op);
   void (*exec)(BMesh *bm, BMOperator *op);
   BMOpTypeFlag type_flag;
 };
diff --git a/source/blender/bmesh/intern/bmesh_operators.cc b/source/blender/bmesh/intern/bmesh_operators.cc
index d56a9b80f5a..becb72e6d52 100644
--- a/source/blender/bmesh/intern/bmesh_operators.cc
+++ b/source/blender/bmesh/intern/bmesh_operators.cc
@@ -157,6 +157,10 @@ void BMO_op_init(BMesh *bm, BMOperator *op, const int flag, const char *opname)
   /* memarena, used for operator's slot buffers */
   op->arena = BLI_memarena_new(BLI_MEMARENA_STD_BUFSIZE, __func__);
   BLI_memarena_use_calloc(op->arena);
+
+  if (bmo_opdefines[opcode]->init) {
+    bmo_opdefines[opcode]->init(op);
+  }
 }
 
 void BMO_op_exec(BMesh *bm, BMOperator *op)
diff --git a/source/blender/bmesh/intern/bmesh_operators_private.hh b/source/blender/bmesh/intern/bmesh_operators_private.hh
index 823caa2e672..e6b3e022c76 100644
--- a/source/blender/bmesh/intern/bmesh_operators_private.hh
+++ b/source/blender/bmesh/intern/bmesh_operators_private.hh
@@ -35,6 +35,7 @@ void bmo_create_monkey_exec(BMesh *bm, BMOperator *op);
 void bmo_create_uvsphere_exec(BMesh *bm, BMOperator *op);
 void bmo_create_vert_exec(BMesh *bm, BMOperator *op);
 void bmo_delete_exec(BMesh *bm, BMOperator *op);
+void bmo_dissolve_edges_init(BMOperator *op);
 void bmo_dissolve_edges_exec(BMesh *bm, BMOperator *op);
 void bmo_dissolve_faces_exec(BMesh *bm, BMOperator *op);
 void bmo_dissolve_verts_exec(BMesh *bm, BMOperator *op);
diff --git a/source/blender/bmesh/operators/bmo_dissolve.cc b/source/blender/bmesh/operators/bmo_dissolve.cc
index f377a0dd269..a5e1621d311 100644
--- a/source/blender/bmesh/operators/bmo_dissolve.cc
+++ b/source/blender/bmesh/operators/bmo_dissolve.cc
@@ -374,6 +374,12 @@ static BMVert *bmo_find_end_of_chain(BMEdge *e, BMVert *v)
   return v;
 }
 
+void bmo_dissolve_edges_init(BMOperator *op)
+{
+  /* Set the default not to limit dissolving at all. */
+  BMO_slot_float_set(op->slots_in, "angle_threshold", M_PI);
+}
+
 void bmo_dissolve_edges_exec(BMesh *bm, BMOperator *op)
 {
   // BMOperator fop;