From 6e94ca7c5647de1f34af504f5d3a464e57a97cd6 Mon Sep 17 00:00:00 2001
From: Zeta <53486764+Apprentice-Alchemist@users.noreply.github.com>
Date: Tue, 4 Mar 2025 06:37:43 +0100
Subject: [PATCH] =?UTF-8?q?Fix=20tmpvar=20redefinition=20when=20incrementi?=
 =?UTF-8?q?ng=20a=20abstract=20array=20access=20exp=E2=80=A6=20(#12034)?=
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* Fix tmpvar redefinition when incrementing a abstract array access expression involving null coalescing.

* Delete redundant .gitignore.
---
 src/typing/operators.ml                       |  5 ++++-
 tests/misc/cpp/projects/Issue12027/Main.hx    | 21 +++++++++++++++++++
 .../misc/cpp/projects/Issue12027/compile.hxml |  2 ++
 3 files changed, 27 insertions(+), 1 deletion(-)
 create mode 100644 tests/misc/cpp/projects/Issue12027/Main.hx
 create mode 100644 tests/misc/cpp/projects/Issue12027/compile.hxml

diff --git a/src/typing/operators.ml b/src/typing/operators.ml
index 8be57597129..b893dd290aa 100644
--- a/src/typing/operators.ml
+++ b/src/typing/operators.ml
@@ -984,6 +984,9 @@ let type_unop ctx op flag e with_type p =
 			| AKAccess(a,tl,c,ebase,ekey) ->
 				begin try
 					(match op with Increment | Decrement -> () | _ -> raise Not_found);
+					let v_base = alloc_var VGenerated "tmp" ebase.etype ebase.epos in
+					let evar_base = mk (TVar(v_base, Some ebase)) ctx.com.basic.tvoid ebase.epos in
+					let ebase = mk (TLocal v_base) ebase.etype ebase.epos in
 					let v_key = alloc_var VGenerated "tmp" ekey.etype ekey.epos in
 					let evar_key = mk (TVar(v_key,Some ekey)) ctx.com.basic.tvoid ekey.epos in
 					let ekey = mk (TLocal v_key) ekey.etype ekey.epos in
@@ -997,7 +1000,7 @@ let type_unop ctx op flag e with_type p =
 					let e_op = mk (TBinop((if op = Increment then OpAdd else OpSub),ev_get,e_one)) ev_get.etype p in
 					(* set *)
 					let e_set = mk_array_set_call ctx (AbstractCast.find_array_write_access_raise ctx a tl ekey e_op p) c ebase p in
-					let el = evar_key :: evar_get :: e_set :: (if flag = Postfix then [ev_get] else []) in
+					let el = evar_base :: evar_key :: evar_get :: e_set :: (if flag = Postfix then [ev_get] else []) in
 					mk (TBlock el) e_set.etype p
 				with Not_found ->
 					let e = mk_array_get_call ctx (AbstractCast.find_array_read_access ctx a tl ekey p) c ebase p in
diff --git a/tests/misc/cpp/projects/Issue12027/Main.hx b/tests/misc/cpp/projects/Issue12027/Main.hx
new file mode 100644
index 00000000000..418ba8f58b4
--- /dev/null
+++ b/tests/misc/cpp/projects/Issue12027/Main.hx
@@ -0,0 +1,21 @@
+function main() {
+	foo(new Foo());
+}
+
+function foo(foo:Null<Foo>) {
+	(foo ?? throw "hello")[0]++;
+}
+
+abstract Foo(Int) {
+	public function new() {
+		this = 0;
+	}
+
+	@:op([]) function get(i:Int) {
+		return this;
+	}
+
+	@:op([]) function set(i:Int, val:Int) {
+		return this;
+	}
+}
diff --git a/tests/misc/cpp/projects/Issue12027/compile.hxml b/tests/misc/cpp/projects/Issue12027/compile.hxml
new file mode 100644
index 00000000000..cf54a5789e3
--- /dev/null
+++ b/tests/misc/cpp/projects/Issue12027/compile.hxml
@@ -0,0 +1,2 @@
+-m Main
+-cpp out
\ No newline at end of file