From 18d390883efc7eaf5ced77d89abc5b51c8b7f816 Mon Sep 17 00:00:00 2001
From: Cai Bear <git@caibear.com>
Date: Sat, 23 Mar 2024 21:27:59 -0700
Subject: [PATCH] Remove len argument from RawVec::reserve_for_push because
 it's always equal to capacity. Also make Vec::insert use reserve_for_push.

---
 library/alloc/src/collections/vec_deque/mod.rs | 5 ++---
 library/alloc/src/raw_vec.rs                   | 4 ++--
 library/alloc/src/vec/mod.rs                   | 4 ++--
 3 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/library/alloc/src/collections/vec_deque/mod.rs b/library/alloc/src/collections/vec_deque/mod.rs
index 41adc2e79dc..742daea873e 100644
--- a/library/alloc/src/collections/vec_deque/mod.rs
+++ b/library/alloc/src/collections/vec_deque/mod.rs
@@ -2086,10 +2086,9 @@ impl<T, A: Allocator> VecDeque<T, A> {
         // Extend or possibly remove this assertion when valid use-cases for growing the
         // buffer without it being full emerge
         debug_assert!(self.is_full());
-        let old_cap = self.capacity();
-        self.buf.reserve_for_push(old_cap);
+        self.buf.reserve_for_push();
         unsafe {
-            self.handle_capacity_increase(old_cap);
+            self.handle_capacity_increase(self.capacity());
         }
         debug_assert!(!self.is_full());
     }
diff --git a/library/alloc/src/raw_vec.rs b/library/alloc/src/raw_vec.rs
index 175e23b543c..45258cc86ff 100644
--- a/library/alloc/src/raw_vec.rs
+++ b/library/alloc/src/raw_vec.rs
@@ -349,8 +349,8 @@ impl<T, A: Allocator> RawVec<T, A> {
     /// oft-instantiated `Vec::push()`, which does its own capacity check.
     #[cfg(not(no_global_oom_handling))]
     #[inline(never)]
-    pub fn reserve_for_push(&mut self, len: usize) {
-        if let Err(err) = self.grow_amortized(len, 1) {
+    pub fn reserve_for_push(&mut self) {
+        if let Err(err) = self.grow_amortized(self.cap.0, 1) {
             handle_error(err);
         }
     }
diff --git a/library/alloc/src/vec/mod.rs b/library/alloc/src/vec/mod.rs
index 8ca8046dac5..5f4c45d578d 100644
--- a/library/alloc/src/vec/mod.rs
+++ b/library/alloc/src/vec/mod.rs
@@ -1547,7 +1547,7 @@ impl<T, A: Allocator> Vec<T, A> {
 
         // space for the new element
         if len == self.buf.capacity() {
-            self.reserve(1);
+            self.buf.reserve_for_push();
         }
 
         unsafe {
@@ -1967,7 +1967,7 @@ impl<T, A: Allocator> Vec<T, A> {
         // This will panic or abort if we would allocate > isize::MAX bytes
         // or if the length increment would overflow for zero-sized types.
         if self.len == self.buf.capacity() {
-            self.buf.reserve_for_push(self.len);
+            self.buf.reserve_for_push();
         }
         unsafe {
             let end = self.as_mut_ptr().add(self.len);