From e50987df4dd7160c237c885f0a92f02ff1c660b0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Adri=C3=A0=20Arrufat?=
 <1671644+arrufat@users.noreply.github.com>
Date: Tue, 6 Sep 2022 05:00:46 +0900
Subject: [PATCH] Fix visitor when tag layer is followed by skip layer (#2662)

---
 dlib/dnn/visitors.h         | 9 +++++++++
 docs/docs/release_notes.xml | 1 +
 2 files changed, 10 insertions(+)

diff --git a/dlib/dnn/visitors.h b/dlib/dnn/visitors.h
index bd0c75efc..a8003cc6e 100644
--- a/dlib/dnn/visitors.h
+++ b/dlib/dnn/visitors.h
@@ -608,6 +608,15 @@ namespace dlib
                 // update(i);
             }
 
+            // Handle the special case when the tag layer is followed by a skip layer
+            template <unsigned long ID, template <typename> class TAG, typename U, typename E>
+            void operator()(size_t i, const add_tag_layer<ID, add_skip_layer<TAG, U>, E>&)
+            {
+                tagged_layers.push_back(i);
+                const auto t = tag_id<TAG>::id;
+                tag_to_layer.at(t) = from;
+            }
+
             template <template <typename> class TAG, typename U>
             void operator()(size_t, const add_skip_layer<TAG, U>&)
             {
diff --git a/docs/docs/release_notes.xml b/docs/docs/release_notes.xml
index 9a08513e8..8dd23163b 100644
--- a/docs/docs/release_notes.xml
+++ b/docs/docs/release_notes.xml
@@ -21,6 +21,7 @@ Non-Backwards Compatible Changes:
 
 Bug fixes:
    - Fix saving grayscale WebP images (PR #2591)
+   - Fix dnn dot visitor when a tag layer is followed by a skip layer (PR #2662)
 </current>
 
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