From 9e002cd7a3f1c6e59cf6de73d45b416f4593e6e7 Mon Sep 17 00:00:00 2001
From: Javier Peletier <jpeletier@users.noreply.github.com>
Date: Sun, 13 Jul 2025 23:58:52 +0200
Subject: [PATCH] [substitutions] Fix #7189 (#9469)

---
 esphome/components/substitutions/__init__.py               | 7 +++++--
 .../fixtures/substitutions/00-simple_var.approved.yaml     | 2 ++
 .../fixtures/substitutions/00-simple_var.input.yaml        | 2 ++
 .../fixtures/substitutions/03-closures.approved.yaml       | 1 +
 .../fixtures/substitutions/closures_package.yaml           | 1 +
 5 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/esphome/components/substitutions/__init__.py b/esphome/components/substitutions/__init__.py
index 5c346ea616..e494529b9e 100644
--- a/esphome/components/substitutions/__init__.py
+++ b/esphome/components/substitutions/__init__.py
@@ -146,8 +146,11 @@ def _substitute_item(substitutions, item, path, jinja, ignore_missing):
             if sub is not None:
                 item[k] = sub
         for old, new in replace_keys:
-            item[new] = merge_config(item.get(old), item.get(new))
-            del item[old]
+            if str(new) == str(old):
+                item[new] = item[old]
+            else:
+                item[new] = merge_config(item.get(old), item.get(new))
+                del item[old]
     elif isinstance(item, str):
         sub = _expand_substitutions(substitutions, item, path, jinja, ignore_missing)
         if isinstance(sub, JinjaStr) or sub != item:
diff --git a/tests/unit_tests/fixtures/substitutions/00-simple_var.approved.yaml b/tests/unit_tests/fixtures/substitutions/00-simple_var.approved.yaml
index c031399c37..f5d2f8aa20 100644
--- a/tests/unit_tests/fixtures/substitutions/00-simple_var.approved.yaml
+++ b/tests/unit_tests/fixtures/substitutions/00-simple_var.approved.yaml
@@ -17,3 +17,5 @@ test_list:
   - ${undefined_var}
   - $undefined_var
   - ${ undefined_var }
+  - key1: 1
+    key2: 2
diff --git a/tests/unit_tests/fixtures/substitutions/00-simple_var.input.yaml b/tests/unit_tests/fixtures/substitutions/00-simple_var.input.yaml
index 88a4ffb991..5717433c7e 100644
--- a/tests/unit_tests/fixtures/substitutions/00-simple_var.input.yaml
+++ b/tests/unit_tests/fixtures/substitutions/00-simple_var.input.yaml
@@ -19,3 +19,5 @@ test_list:
   - ${undefined_var}
   - $undefined_var
   - ${ undefined_var }
+  - key${var1}: 1
+    key${var2}: 2
diff --git a/tests/unit_tests/fixtures/substitutions/03-closures.approved.yaml b/tests/unit_tests/fixtures/substitutions/03-closures.approved.yaml
index c8f7d9976c..dad3be8aa7 100644
--- a/tests/unit_tests/fixtures/substitutions/03-closures.approved.yaml
+++ b/tests/unit_tests/fixtures/substitutions/03-closures.approved.yaml
@@ -6,6 +6,7 @@ package_result:
     root file
   - Double substitution also works; the value of var7 is 79, where A is a package
     var
+  - key79: Key should substitute to key79
 local_results:
   - The value of B is 5
   - 'You will see, however, that
diff --git a/tests/unit_tests/fixtures/substitutions/closures_package.yaml b/tests/unit_tests/fixtures/substitutions/closures_package.yaml
index e87908814d..4a0be24b93 100644
--- a/tests/unit_tests/fixtures/substitutions/closures_package.yaml
+++ b/tests/unit_tests/fixtures/substitutions/closures_package.yaml
@@ -1,3 +1,4 @@
 package_result:
   - The value of A*B is ${A * B}, where A is a package var and B is a substitution in the root file
   - Double substitution also works; the value of var7 is ${var$A}, where A is a package var
+  - key${var7}: Key should substitute to key79