From 7679e11a261aa4e6e40cb9d5222b9f81edca1990 Mon Sep 17 00:00:00 2001
From: jajhall <jajhall@ed.ac.uk>
Date: Sun, 30 Jun 2024 16:36:45 +0100
Subject: [PATCH] Moved pdlp_iteration_count back to where it was inserted,
 breaking the C API

---
 FEATURES.md                       | 42 +++++++------------------------
 src/lp_data/HighsCallbackStruct.h |  2 +-
 2 files changed, 10 insertions(+), 34 deletions(-)

diff --git a/FEATURES.md b/FEATURES.md
index 09784c9767..98dc828433 100644
--- a/FEATURES.md
+++ b/FEATURES.md
@@ -1,41 +1,17 @@
 ## Build changes
 
-### HiGHS on nixpkgs
-
-HiGHS now has a `flake.nix` to build the binary, allowing `nix` users to try it out
-
-### Python build update
-
-Highspy with setuptools from v1.7.0 only worked on Python 3.12
-For v1.7.0 we have dropped setuptools and switched to scikit-build-core
-
-### Windows versions
-
-Fixed version info of shared library
-Added version info to executable
-
 ## Code changes
 
-Inserting `pdlp_iteration_count` into various structs (for v1.7.0) breaks the C API, so it has been moved to the end of those structs
-
-`setBasis` has been added to `highspy`
-
-`writePresolvedModel` has been added
-
-Saved MIP solution pool is populated when presolve reduces MIP to empty
-
-Compilation date has been removed improve build reproducibility. Methods to print compilation dates are deprecated
-
-Logging and error return when user-supplied solution or basis is rejected on vector dimensions
-
-Memory allocation errors in presolve are caught and `Highs::run()` returns `HighsStatus::kError` with `model_status_ = HighsModelStatus::kMemoryLimit`
-
-QP solver logging is now neater and quieter
-
-Any Hessian for the incumbent model is modified with zero entries when adding columns to the model, and rows/columns are removed when columns are deleted from the model.
+The accessor function Highs_getCallbackDataOutItem in the C API means
+that `pdlp_iteration_count` can be moved back to where it was inserted
+into the `HighsCallbackDataOut` struct in v1.7.0, which broke the C
+API. This fixes #1812
 
-Minor bug fix in MIP presolve
+Some duplicate code has been eliminated from the MIP solver, and
+modifications made to eliminate compiler warnings
 
-QP solver will now hot start given a basis and solution
+Declaration of the (deprecated) method `char* highsCompilationDate()`
+has been corrected
 
+Fixed bug when describing integrality status during the human-readable solution write
 
diff --git a/src/lp_data/HighsCallbackStruct.h b/src/lp_data/HighsCallbackStruct.h
index 237eb30c74..b76716d3eb 100644
--- a/src/lp_data/HighsCallbackStruct.h
+++ b/src/lp_data/HighsCallbackStruct.h
@@ -29,6 +29,7 @@ typedef struct {
   double running_time;
   HighsInt simplex_iteration_count;
   HighsInt ipm_iteration_count;
+  HighsInt pdlp_iteration_count;
   double objective_function_value;
   int64_t mip_node_count;
   double mip_primal_bound;
@@ -43,7 +44,6 @@ typedef struct {
   double* cutpool_value;
   double* cutpool_lower;
   double* cutpool_upper;
-  HighsInt pdlp_iteration_count;
 } HighsCallbackDataOut;
 
 typedef struct {