From 96df32024d8d2cca247413fa88637e15cf0e217a Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Fri, 2 Oct 2026 21:17:19 -0500
Subject: [PATCH] [core] Let shared_progmem_array emit an unshared array

Identical lambdas can carry separate static state, so callers need a way
to keep such tables apart while still getting a collision free name.
---
 esphome/cpp_generator.py               | 24 ++++++++++++++----------
 tests/unit_tests/test_cpp_generator.py |  7 +++++++
 2 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/esphome/cpp_generator.py b/esphome/cpp_generator.py
index ee018e9dea1..a5ffaefe0be 100644
--- a/esphome/cpp_generator.py
+++ b/esphome/cpp_generator.py
@@ -469,12 +469,13 @@ def progmem_array(id_, rhs) -> "MockObj":
 
 
 def shared_progmem_array(
-    name: str, type_: "MockObjClass", rhs: SafeExpType
+    name: str, type_: "MockObjClass", rhs: SafeExpType, *, share: bool = True
 ) -> "MockObj":
     """Emit a global PROGMEM array once per distinct type and contents; later calls reuse it.
 
     The array is ``static constexpr``, so elements must be constant expressions and lambdas
     must be captureless. Its name is made unique against every config id and variable.
+    ``share=False`` always emits a new array, e.g. for lambdas that may keep static state.
     """
     from esphome.config import iter_ids
     from esphome.config_validation import RESERVED_IDS
@@ -482,15 +483,18 @@ def shared_progmem_array(
     arrays: dict[str, MockObj] = CORE.data.setdefault("shared_progmem_array", {})
     rhs = safe_exp(rhs)
     key = f"{type_} {rhs}"
-    if (array := arrays.get(key)) is None:
-        used = {str(i) for i, _ in iter_ids(CORE.config)}
-        used |= {str(i) for i in CORE.variables}
-        used |= set(RESERVED_IDS) | CORE.loaded_integrations
-        id_ = ID(ensure_unique_string(name, used), is_declaration=True, type=type_)
-        # Global, so any scope can use it; anything a lambda references is already declared.
-        CORE.add_global(ProgmemAssignmentExpression(type_, id_, rhs))
-        array = arrays[key] = MockObj(id_, ".")
-        CORE.register_variable(id_, array)
+    if share and (array := arrays.get(key)) is not None:
+        return array
+    used = {str(i) for i, _ in iter_ids(CORE.config)}
+    used |= {str(i) for i in CORE.variables}
+    used |= set(RESERVED_IDS) | CORE.loaded_integrations
+    id_ = ID(ensure_unique_string(name, used), is_declaration=True, type=type_)
+    # Global, so any scope can use it; anything a lambda references is already declared.
+    CORE.add_global(ProgmemAssignmentExpression(type_, id_, rhs))
+    array = MockObj(id_, ".")
+    CORE.register_variable(id_, array)
+    if share:
+        arrays[key] = array
     return array
 
 
diff --git a/tests/unit_tests/test_cpp_generator.py b/tests/unit_tests/test_cpp_generator.py
index 0ee6d1ae5ca..06b7c56baeb 100644
--- a/tests/unit_tests/test_cpp_generator.py
+++ b/tests/unit_tests/test_cpp_generator.py
@@ -822,6 +822,13 @@ class TestSharedProgmemArray:
         assert sum("PROGMEM" in str(st) for st in CORE.global_statements) == 2
         assert not any("PROGMEM" in str(st) for st in CORE.main_statements)
 
+    def test_share_false_always_emits_a_new_array(self) -> None:
+        CORE.config = {}
+        a = cg.shared_progmem_array("table", ct.uint8, [1], share=False)
+        b = cg.shared_progmem_array("table", ct.uint8, [1], share=False)
+        assert str(a) != str(b)
+        assert sum("PROGMEM" in str(st) for st in CORE.global_statements) == 2
+
     def test_same_contents_different_type_are_separate(self) -> None:
         CORE.config = {}
         a = cg.shared_progmem_array("table", ct.uint8, [1])