From db391a256f783392760ecdfeafbceea9d926c586 Mon Sep 17 00:00:00 2001
From: Penelope Yong <penelopeysm@gmail.com>
Date: Fri, 25 Oct 2024 03:05:52 +0100
Subject: [PATCH 1/2] Special-case ReshapeTransform for singleton inputs

---
 Project.toml |  2 +-
 src/utils.jl | 11 +++++++++--
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/Project.toml b/Project.toml
index eab8c362c..92fb67ddd 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,6 +1,6 @@
 name = "DynamicPPL"
 uuid = "366bfd00-2699-11ea-058f-f148b4cae6d8"
-version = "0.30.1"
+version = "0.30.2"
 
 [deps]
 ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"
diff --git a/src/utils.jl b/src/utils.jl
index bd5d365fc..1a2d1ffd7 100644
--- a/src/utils.jl
+++ b/src/utils.jl
@@ -286,8 +286,15 @@ function (f::ReshapeTransform)(x)
     if size(x) != f.input_size
         throw(DimensionMismatch("Expected input of size $(f.input_size), got $(size(x))"))
     end
-    # The call to `tovec` is only needed in case `x` is a scalar.
-    return reshape(tovec(x), f.output_size)
+    if f.output_size == ()
+        # Specially handle the case where x is a singleton array, see
+        # https://github.com/JuliaDiff/ReverseDiff.jl/issues/265 and
+        # https://github.com/TuringLang/DynamicPPL.jl/issues/698
+        return x[]
+    else
+        # The call to `tovec` is only needed in case `x` is a scalar.
+        return reshape(tovec(x), f.output_size)
+    end
 end
 
 function (inv_f::Bijectors.Inverse{<:ReshapeTransform})(x)

From 8c9cc716d1211bf7f45cb8dc0dbc07bf23b7a4c4 Mon Sep 17 00:00:00 2001
From: Penelope Yong <penelopeysm@gmail.com>
Date: Fri, 25 Oct 2024 11:31:23 +0100
Subject: [PATCH 2/2] Use fill(x[], ()) instead

---
 src/utils.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/utils.jl b/src/utils.jl
index 1a2d1ffd7..a809fda17 100644
--- a/src/utils.jl
+++ b/src/utils.jl
@@ -290,7 +290,7 @@ function (f::ReshapeTransform)(x)
         # Specially handle the case where x is a singleton array, see
         # https://github.com/JuliaDiff/ReverseDiff.jl/issues/265 and
         # https://github.com/TuringLang/DynamicPPL.jl/issues/698
-        return x[]
+        return fill(x[], ())
     else
         # The call to `tovec` is only needed in case `x` is a scalar.
         return reshape(tovec(x), f.output_size)