From bb90f3c36c6746a618523df0de20441dd3517561 Mon Sep 17 00:00:00 2001
From: jumerckx <31353884+jumerckx@users.noreply.github.com>
Date: Wed, 21 May 2025 22:21:35 +0200
Subject: [PATCH] allow path==nothing

This seemed nice to have when using make_tracer as utility to clone
objects. I don't think I actually use it already in the function call
insertion, but I think there's places where I could.
---
 src/Tracing.jl | 28 +++++++++++++++++++---------
 1 file changed, 19 insertions(+), 9 deletions(-)

diff --git a/src/Tracing.jl b/src/Tracing.jl
index e110407c05..fefc4dfb2f 100644
--- a/src/Tracing.jl
+++ b/src/Tracing.jl
@@ -961,6 +961,7 @@ function make_tracer(
     return prev
 end
 append_path(@nospecialize(path), i) = (path..., i)
+append_path(::Nothing, i) = nothing
 
 Base.@nospecializeinfer function make_tracer_via_immutable_constructor(
     seen,
@@ -1283,21 +1284,24 @@ Base.@nospecializeinfer function make_tracer(
         return nothing
     end
     if mode == TracedTrack
-        TracedUtils.set_paths!(prev, (TracedUtils.get_paths(prev)..., path))
+        !isnothing(path) &&
+            TracedUtils.set_paths!(prev, (TracedUtils.get_paths(prev)..., path))
         if !haskey(seen, prev)
             return seen[prev] = prev
         end
         return prev
     end
     if mode == NoStopTracedTrack
-        TracedUtils.set_paths!(prev, (TracedUtils.get_paths(prev)..., path))
+        !isnothing(path) &&
+            TracedUtils.set_paths!(prev, (TracedUtils.get_paths(prev)..., path))
         if !haskey(seen, prev)
             seen[prev] = prev # don't return!
         end
         return prev
     end
     if mode == TracedSetPath
-        TracedUtils.set_paths!(prev, (TracedUtils.get_paths(prev)..., path))
+        !isnothing(path) &&
+            TracedUtils.set_paths!(prev, (TracedUtils.get_paths(prev)..., path))
         if haskey(seen, prev)
             return seen[prev]
         end
@@ -1361,21 +1365,24 @@ Base.@nospecializeinfer function make_tracer(
         return nothing
     end
     if mode == TracedTrack
-        TracedUtils.set_paths!(prev, (TracedUtils.get_paths(prev)..., path))
+        !isnothing(path) &&
+            TracedUtils.set_paths!(prev, (TracedUtils.get_paths(prev)..., path))
         if !haskey(seen, prev)
             return seen[prev] = prev
         end
         return prev
     end
     if mode == NoStopTracedTrack
-        TracedUtils.set_paths!(prev, (TracedUtils.get_paths(prev)..., path))
+        !isnothing(path) &&
+            TracedUtils.set_paths!(prev, (TracedUtils.get_paths(prev)..., path))
         if !haskey(seen, prev)
             seen[prev] = prev # don't return!
         end
         return prev
     end
     if mode == TracedSetPath
-        TracedUtils.set_paths!(prev, (TracedUtils.get_paths(prev)..., path))
+        !isnothing(path) &&
+            TracedUtils.set_paths!(prev, (TracedUtils.get_paths(prev)..., path))
         if haskey(seen, prev)
             return seen[prev]
         end
@@ -1430,21 +1437,24 @@ Base.@nospecializeinfer function make_tracer(
         throw("Cannot have MissingTracedValue as function call argument.")
     end
     if mode == TracedTrack
-        TracedUtils.set_paths!(prev, (TracedUtils.get_paths(prev)..., path))
+        !isnothing(path) &&
+            TracedUtils.set_paths!(prev, (TracedUtils.get_paths(prev)..., path))
         if !haskey(seen, prev)
             return seen[prev] = prev
         end
         return prev
     end
     if mode == NoStopTracedTrack
-        TracedUtils.set_paths!(prev, (TracedUtils.get_paths(prev)..., path))
+        !isnothing(path) &&
+            TracedUtils.set_paths!(prev, (TracedUtils.get_paths(prev)..., path))
         if !haskey(seen, prev)
             seen[prev] = prev # don't return!
         end
         return prev
     end
     if mode == TracedSetPath
-        TracedUtils.set_paths!(prev, (TracedUtils.get_paths(prev)..., path))
+        !isnothing(path) &&
+            TracedUtils.set_paths!(prev, (TracedUtils.get_paths(prev)..., path))
         haskey(seen, prev) && return seen[prev]
         res = MissingTracedValue((path,))
         seen[res] = res