From b6150158830eb9bf3454554a483be4871ba50d63 Mon Sep 17 00:00:00 2001
From: Daniel Thom <daniel.thom@nrel.gov>
Date: Mon, 3 Feb 2025 13:25:02 -0700
Subject: [PATCH 1/2] Fix set_bus_number!

This fixes a bug in a12f90349e2aadfc2f9fbeee23276115099ead08. It was
leaving the original bus number in sys.bus_numbers.
---
 src/base.jl         | 12 ++++++++++--
 test/test_system.jl | 18 ++++++++++++++++++
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/src/base.jl b/src/base.jl
index 40d9c4e67b..41bfa57b53 100644
--- a/src/base.jl
+++ b/src/base.jl
@@ -2623,11 +2623,19 @@ end
 Set the number of a bus.
 """
 function set_bus_number!(sys::System, bus::ACBus, number::Int)
+    throw_if_not_attached(bus, sys)
+
+    orig = get_number(bus)
+    if number == orig
+        return
+    end
+
     if number in sys.bus_numbers
         throw(ArgumentError("bus number $number is already stored in the system"))
     end
-    bus.number = number
-    push!(sys.bus_numbers, number)
+
+    set_number!(bus, number)
+    replace!(sys.bus_numbers, orig => number)
     return
 end
 
diff --git a/test/test_system.jl b/test/test_system.jl
index 4a6c4fece6..14e7e7d1e2 100644
--- a/test/test_system.jl
+++ b/test/test_system.jl
@@ -625,5 +625,23 @@ end
     @test orig != new_number
     set_bus_number!(sys, bus1, new_number)
     @test get_number(bus1) == new_number
+    bus_numbers = get_bus_numbers(sys)
+    @test new_number in bus_numbers
+    @test !(orig in bus_numbers)
+
+    # Ensure that the no-op case works.
+    set_bus_number!(sys, bus1, new_number)
+    @test get_number(bus1) == new_number
+    @test new_number in get_bus_numbers(sys)
+
+    # Ensure that duplicate numbers are blocked.
     @test_throws ArgumentError set_bus_number!(sys, bus1, get_number(bus2))
+
+    # Ensure that you can't change an unattached bus.
+    remove_component!(sys, bus1)
+    @test_throws ArgumentError set_bus_number!(sys, bus1, new_number + 1)
+
+    # Ensure that this is exported. This can be deleted in PSY5.
+    set_number!(bus1, new_number + 2)
+    @test get_number(bus1) == new_number + 2
 end

From 9fd6573a45e9bc3f4b9f50a9d0124a2788961fdb Mon Sep 17 00:00:00 2001
From: Daniel Thom <daniel.thom@nrel.gov>
Date: Fri, 31 Jan 2025 18:32:16 -0700
Subject: [PATCH 2/2] Remove workaround for set_number!(::ACBus, ::Int)

---
 src/parsers/psse_metadata_reimport.jl | 18 +++++-------------
 1 file changed, 5 insertions(+), 13 deletions(-)

diff --git a/src/parsers/psse_metadata_reimport.jl b/src/parsers/psse_metadata_reimport.jl
index e848b86aca..f9414fae73 100644
--- a/src/parsers/psse_metadata_reimport.jl
+++ b/src/parsers/psse_metadata_reimport.jl
@@ -75,19 +75,11 @@ function remap_bus_numbers!(sys::System, bus_number_mapping)
         old_number = get_number(bus)
         new_number = parse(Int, bus_number_mapping[old_number])
         if new_number != old_number
-            if new_number in get_bus_numbers(sys)
-                # We would only reach this case if one bus's PSS/E number is another bus's
-                # Sienna number. That never happens because _psse_bus_numbers on the
-                # exporting side guarantees that bus numbers that are already compliant with
-                # the PSS/E spec will not be changed.
-                throw(
-                    ArgumentError(
-                        "Trying to remap bus number $old_number to $new_number, which is already a bus number",
-                    ),
-                )
-            end
-            replace!(sys.bus_numbers, old_number => new_number)
-            set_number!(bus, new_number)
+            # This will throw an exception if one bus's PSS/E number is another bus's
+            # Sienna number. That never happens because _psse_bus_numbers on the
+            # exporting side guarantees that bus numbers that are already compliant with
+            # the PSS/E spec will not be changed.
+            set_bus_number!(sys, bus, new_number)
         end
     end
 end