From 7931f315b13a65c8e4d74283a00f8208cc6bb465 Mon Sep 17 00:00:00 2001
From: Jeff Young <jeff@rokeby.ie>
Date: Sun, 26 Mar 2023 10:59:31 +0100
Subject: [PATCH] Manually cherry-pick some fixes back from master.

Fixes https://gitlab.com/kicad/code/kicad/issues/14424
---
 eeschema/sim/ngspice_circuit_model.cpp | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/eeschema/sim/ngspice_circuit_model.cpp b/eeschema/sim/ngspice_circuit_model.cpp
index 398f16859b..1fa84e2a5f 100644
--- a/eeschema/sim/ngspice_circuit_model.cpp
+++ b/eeschema/sim/ngspice_circuit_model.cpp
@@ -33,17 +33,24 @@
 SIM_PLOT_TYPE NGSPICE_CIRCUIT_MODEL::VectorToSignal( const std::string& aVector,
                                                      wxString& aSignal ) const
 {
-    using namespace std;
-
+    static wxString BRANCH( wxS( "#branch" ) );
     // See ngspice manual chapt. 31.1 "Accessing internal device parameters"
-    wxRegEx  internalDevParameter( "^@(\\w*[\\.\\w+]*)\\[(\\w*)\\]$", wxRE_ADVANCED );
+    static wxRegEx internalDevParameter( wxS( "^@(\\w*[\\.\\w+]*)\\[(\\w*)\\]$" ), wxRE_ADVANCED );
+
     wxString vector( aVector );
 
     if( !internalDevParameter.Matches( vector ) )
     {
-        // any text is a node name, which returns voltage
-        aSignal = wxT( "V(" ) + aVector + wxT( ")" );
-        return SPT_VOLTAGE;
+        if( vector.EndsWith( BRANCH ) )
+        {
+            aSignal = wxT( "I(" ) + vector.Left( vector.Length() - BRANCH.Length() ) + wxT( ")" );
+            return SPT_CURRENT;
+        }
+        else
+        {
+            aSignal = wxT( "V(" ) + vector + wxT( ")" );
+            return SPT_VOLTAGE;
+        }
     }
     else
     {