From 0fd360428acdc7689356861a9c5e01862a5fe1ed Mon Sep 17 00:00:00 2001
From: Brecht Van Lommel <brecht@blender.org>
Date: Fri, 28 Mar 2025 19:25:56 +0100
Subject: [PATCH] Fix #136593, #136641: Quadriflow remesh gets stuck on Windows

This appears to be a pre-existing issue that got exposed by the refactor
for some files, while for others it was already happening.

Pull Request: https://projects.blender.org/blender/blender/pulls/136680
---
 extern/quadriflow/patches/blender.patch       | 31 +++++++++----------
 .../patches/boykov_kolmogorov_max_flow.hpp    |  2 ++
 extern/quadriflow/src/optimizer.cpp           |  4 ++-
 3 files changed, 19 insertions(+), 18 deletions(-)

diff --git a/extern/quadriflow/patches/blender.patch b/extern/quadriflow/patches/blender.patch
index d74bd09f22f..83ca880178d 100644
--- a/extern/quadriflow/patches/blender.patch
+++ b/extern/quadriflow/patches/blender.patch
@@ -521,21 +521,18 @@ index a93c58ac2a7..8c682b6d9f2 100644
                      VectorXi &V2E, VectorXi &E2E, VectorXi &boundary, VectorXi &nonmanifold,
                      std::vector<Vector2i> &edge_diff, std::vector<DEdge> &edge_values,
                      std::vector<Vector3i> &face_edgeOrients, std::vector<Vector3i> &face_edgeIds,
-diff --git a/intern/quadriflow/quadriflow_capi.cpp b/intern/quadriflow/quadriflow_capi.cpp
-index fad604f679a..014ac2a5613 100644
---- a/intern/quadriflow/quadriflow_capi.cpp
-+++ b/intern/quadriflow/quadriflow_capi.cpp
-@@ -190,8 +190,11 @@ void QFLOW_quadriflow_remesh(QuadriflowRemeshData *qrd,
-     return;
-   }
+diff --git a/extern/quadriflow/src/optimizer.cpp b/extern/quadriflow/src/optimizer.cpp
+index 1c59ad0f70c..f8836ed0d0e 100644
+--- a/extern/quadriflow/src/optimizer.cpp
++++ b/extern/quadriflow/src/optimizer.cpp
+@@ -1296,7 +1296,9 @@ void Optimizer::optimize_integer_constraints(Hierarchy& mRes, std::map<int, int>
+                 solver = std::make_unique<GurobiFlowHelper>();
+             }
+ #endif
+-            solver->resize(initial.size() + 2, arc_ids.size());
++            /* This used to be arc_ids.size() which is wrong, the loop below adds
++             * exactly arcs.size() edges. */
++            solver->resize(initial.size() + 2, arcs.size());
  
--  /* Compute the final quad geomtry using a maxflow solver */
--  field.ComputeIndexMap();
-+  /* Compute the final quad geometry using a maxflow solver */
-+  if (!field.ComputeIndexMap()) {
-+    /* Error computing the result. */
-+    return;
-+  }
- 
-   if (check_if_canceled(0.9f, update_cb, update_cb_data)) {
-     return;
+             std::set<int> ids;
+             for (int i = 0; i < arcs.size(); ++i) {
diff --git a/extern/quadriflow/patches/boykov_kolmogorov_max_flow.hpp b/extern/quadriflow/patches/boykov_kolmogorov_max_flow.hpp
index 96df563f0c4..d99b464a537 100644
--- a/extern/quadriflow/patches/boykov_kolmogorov_max_flow.hpp
+++ b/extern/quadriflow/patches/boykov_kolmogorov_max_flow.hpp
@@ -49,6 +49,8 @@ class BoykovKolmogorovMaxFlow {
                 const int target,
                 const int capacity)
   {
+    assert(edge < m_graph_edges.size());
+
     m_graph_edges[edge] = Edge{source, target};
     m_graph_out_edges[source].push_back(edge);
     m_rev_edge_map[edge] = reverse_edge;
diff --git a/extern/quadriflow/src/optimizer.cpp b/extern/quadriflow/src/optimizer.cpp
index 1c59ad0f70c..5e14f329805 100644
--- a/extern/quadriflow/src/optimizer.cpp
+++ b/extern/quadriflow/src/optimizer.cpp
@@ -1296,7 +1296,9 @@ void Optimizer::optimize_integer_constraints(Hierarchy& mRes, std::map<int, int>
                 solver = std::make_unique<GurobiFlowHelper>();
             }
 #endif
-            solver->resize(initial.size() + 2, arc_ids.size());
+            /* This used to be arc_ids.size() which is wrong, the loop below adds
+             * exactly arcs.size() edges. */
+            solver->resize(initial.size() + 2, arcs.size());
 
             std::set<int> ids;
             for (int i = 0; i < arcs.size(); ++i) {