Git crashed on `git apply --check`

From

GGingrspacecadet <jackrawlings2011@gmail.com>

Date

Oct 17, 2026, 15:17 UTC

Message-ID

<CALdwsC1cMKZgRPZA+pBaJe4PPs9q9W0K9CQLmM2bgUCyysTB-w@mail.gmail.com>

diff --git a/tests/constraint_type_signature_lifting.test
b/tests/constraint_type_signature_lifting.test

new file mode 100644
index 0000000..0000000
--- /dev/null
+++ b/tests/constraint_type_signature_lifting.test
@@ -0,0 +1,40 @@
+name: constraint types in signatures are lifted to generic parameters
+expect: pass
+stop: run
+errors: 0
+
+[source]
+constraint Readable = {
+    fn uint64 Readable.read(Readable *self);
+}
+
+type File = struct {
+    uint64 size;
+};
+
+fn uint64 File.read(File *self) {
+    return self.size;
+}
+
+fn Readable identity(Readable value) {
+    return value;
+}
+
+fn uint64 read_size(Readable file) {
+    return file.read();
+}
+
+fn int64 main() {
+    File file = {42};
+    File copy = identity(file);
+    if (copy.size != 42) return 1;
+    if (read_size(file) != 42) return 2;
+    return 0;
+}
+
+[stdout]
+
+[stderr]
+
+[exit]
+0

What did you expect to happen?
The patch check to pass

What happened instead?
"git: apply.c:3856: check_preimage: Assertion `patch->is_new <= 0' failed.i"

[System Info]
git version:
git version 2.54.0
cpu: x86_64
built from commit: 94f057755b7941b321fd11fec1b2e3ca5313a4e0
sizeof-long: 8
sizeof-size_t: 8
shell-path: /bin/sh
rust: enabled
gettext: enabled
libcurl: 8.19.0
OpenSSL: OpenSSL 3.6.2 7 Apr 2026
zlib-ng: 2.3.3
SHA-1: SHA1_DC
SHA-256: SHA256_BLK
default-ref-format: files
default-hash: sha1
uname: Linux 7.0.10-arch1-1 #1 SMP PREEMPT_DYNAMIC Sat, 23 May 2026
14:21:20 +0000 x86_64
compiler info: gnuc: 15.2
libc info: glibc: 2.43
$SHELL (typically, interactive shell): /usr/bin/bash


[Enabled Hooks]