From 23299f19ebca57220af5946764d6aef9bd345cc9 Mon Sep 17 00:00:00 2001
From: odow <o.dowson@gmail.com>
Date: Thu, 16 May 2024 10:37:32 +1200
Subject: [PATCH 1/2] Improve stacktrace of errors thrown from within a
 callback

---
 src/MOI_wrapper/MOI_wrapper.jl |  2 +-
 test/MOI_callbacks.jl          | 19 +++++++++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/src/MOI_wrapper/MOI_wrapper.jl b/src/MOI_wrapper/MOI_wrapper.jl
index d43e7b7..6cdd85a 100644
--- a/src/MOI_wrapper/MOI_wrapper.jl
+++ b/src/MOI_wrapper/MOI_wrapper.jl
@@ -232,7 +232,7 @@ function _internal_callback(tree::Ptr{Cvoid}, info::Ptr{Cvoid})
         cb_data.callback_function(cb_data)
     catch ex
         glp_ios_terminate(tree)
-        cb_data.exception = ex
+        cb_data.exception = CapturedException(ex, catch_backtrace())
     end
     return Cint(0)
 end
diff --git a/test/MOI_callbacks.jl b/test/MOI_callbacks.jl
index 2e5cc13..039331e 100644
--- a/test/MOI_callbacks.jl
+++ b/test/MOI_callbacks.jl
@@ -577,6 +577,25 @@ function test_no_cache_InterruptException()
     return
 end
 
+function test_issue_232()
+    model = GLPK.Optimizer()
+    x = MOI.add_variable(model)
+    MOI.add_constraint(model, x, MOI.ZeroOne())
+    my_callback(args...) = error("FooBar")
+    MOI.set(model, GLPK.CallbackFunction(), my_callback)
+    try
+        MOI.optimize!(model)
+        # To ensure that if an error is not thrown from the callback we still
+        # hit the catch block
+        @assert false
+    catch ex
+        @test ex isa CapturedException
+        @test occursin("my_callback", "$ex")
+        @test occursin("FooBar", "$ex")
+    end
+    return
+end
+
 end
 
 TestCallbacks.runtests()

From 5911b028fe85fffa90baead26fdac44df627bb02 Mon Sep 17 00:00:00 2001
From: odow <o.dowson@gmail.com>
Date: Thu, 16 May 2024 11:01:51 +1200
Subject: [PATCH 2/2] Update

---
 src/MOI_wrapper/MOI_wrapper.jl | 17 +++++++++++++----
 test/MOI_callbacks.jl          |  2 +-
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/src/MOI_wrapper/MOI_wrapper.jl b/src/MOI_wrapper/MOI_wrapper.jl
index 6cdd85a..13b8a20 100644
--- a/src/MOI_wrapper/MOI_wrapper.jl
+++ b/src/MOI_wrapper/MOI_wrapper.jl
@@ -1402,10 +1402,19 @@ function _solve_mip_problem(model::Optimizer)
         #
         #  This next bit is _very_ important! See the note associated with
         #  set_callback.
-        if model.callback_data.exception isa InterruptException
-            model.solver_status = GLP_ESTOP
-        elseif model.callback_data.exception !== nothing
-            throw(model.callback_data.exception)
+        if model.callback_data.exception !== nothing
+            model.callback_data.exception::CapturedException
+            inner = model.callback_data.exception.ex
+            if inner isa InterruptException
+                model.solver_status = GLP_ESTOP
+            elseif inner isa MOI.InvalidCallbackUsage
+                # Special-case throwing InvalidCallbackUsage to preserve
+                # backwards compatibility. But it does mean that they don't have
+                # good backtraces...
+                throw(inner)
+            else
+                throw(model.callback_data.exception)
+            end
         end
     finally
         for (column, lower, upper) in bounds_to_reset
diff --git a/test/MOI_callbacks.jl b/test/MOI_callbacks.jl
index 039331e..01bee3e 100644
--- a/test/MOI_callbacks.jl
+++ b/test/MOI_callbacks.jl
@@ -577,7 +577,7 @@ function test_no_cache_InterruptException()
     return
 end
 
-function test_issue_232()
+function test_no_cache_issue_232()
     model = GLPK.Optimizer()
     x = MOI.add_variable(model)
     MOI.add_constraint(model, x, MOI.ZeroOne())