--- firefox-78.9.0/Cargo.lock.D87019-thin-vec-big-endian.diff	2021-03-18 15:53:29.520861862 +0100

+++ firefox-78.9.0/Cargo.lock	2021-03-18 15:56:14.193397228 +0100

@@ -4792,9 +4792,9 @@ checksum = "8eaa81235c7058867fa8c0e7314f

 [[package]]

 name = "thin-vec"

-version = "0.1.2"

+version = "0.2.1"

 source = "registry+https://github.com/rust-lang/crates.io-index"

-checksum = "3a93c9ade36a827a69257925808463db46ffcf193442fad01eb9bdc1d31aed81"

+checksum = "dcc760ada4a9f56fc6d0e81bd143984ebc7bb1b875a6891aa2fa613ca7394fc0"

 [[package]]

 name = "thiserror"

--- firefox-78.9.0/gfx/webrender_bindings/Cargo.toml.D87019-thin-vec-big-endian.diff	2021-03-15 16:52:33.000000000 +0100

+++ firefox-78.9.0/gfx/webrender_bindings/Cargo.toml	2021-03-18 15:53:29.522861856 +0100

@@ -20,7 +20,7 @@ nsstring = { path = "../../xpcom/rust/ns

 bincode = "1.0"

 uuid = { version = "0.8", features = ["v4"] }

 fxhash = "0.2.1"

-thin-vec = { version = "0.1.0", features = ["gecko-ffi"] }

+thin-vec = { version = "0.2.1", features = ["gecko-ffi"] }

 swgl = { path = "../wr/swgl" }

 [dependencies.webrender]

--- firefox-78.9.0/intl/l10n/rust/fluent-ffi/Cargo.toml.D87019-thin-vec-big-endian.diff	2021-03-15 16:52:33.000000000 +0100

+++ firefox-78.9.0/intl/l10n/rust/fluent-ffi/Cargo.toml	2021-03-18 15:53:29.524861850 +0100

@@ -10,4 +10,4 @@ fluent-pseudo = "0.2"

 intl-memoizer = "0.4"

 unic-langid = "0.8"

 nsstring = { path = "../../../../xpcom/rust/nsstring" }

-thin-vec = { version = "0.1.0", features = ["gecko-ffi"] }

+thin-vec = { version = "0.2.1", features = ["gecko-ffi"] }

--- firefox-78.9.0/intl/locale/rust/fluent-langneg-ffi/Cargo.toml.D87019-thin-vec-big-endian.diff	2021-03-15 16:52:33.000000000 +0100

+++ firefox-78.9.0/intl/locale/rust/fluent-langneg-ffi/Cargo.toml	2021-03-18 15:53:29.525861847 +0100

@@ -9,7 +9,7 @@ edition = "2018"

 nserror = { path = "../../../../xpcom/rust/nserror" }

 nsstring = { path = "../../../../xpcom/rust/nsstring" }

 xpcom = { path = "../../../../xpcom/rust/xpcom" }

-thin-vec = { version = "0.1.0", features = ["gecko-ffi"] }

+thin-vec = { version = "0.2.1", features = ["gecko-ffi"] }

 fluent-langneg = { version = "0.12.1", features = ["cldr"] }

 unic-langid = "0.8"

 unic-langid-ffi = { path = "../unic-langid-ffi" }

--- firefox-78.9.0/intl/locale/rust/unic-langid-ffi/Cargo.toml.D87019-thin-vec-big-endian.diff	2021-03-15 16:52:33.000000000 +0100

+++ firefox-78.9.0/intl/locale/rust/unic-langid-ffi/Cargo.toml	2021-03-18 15:53:29.526861844 +0100

@@ -9,5 +9,5 @@ edition = "2018"

 nserror = { path = "../../../../xpcom/rust/nserror" }

 nsstring = { path = "../../../../xpcom/rust/nsstring" }

 xpcom = { path = "../../../../xpcom/rust/xpcom" }

-thin-vec = { version = "0.1.0", features = ["gecko-ffi"] }

+thin-vec = { version = "0.2.1", features = ["gecko-ffi"] }

 unic-langid = { version = "0.8", features = ["likelysubtags"] }

--- firefox-78.9.0/netwerk/socket/neqo_glue/Cargo.toml.D87019-thin-vec-big-endian.diff	2021-03-15 16:52:37.000000000 +0100

+++ firefox-78.9.0/netwerk/socket/neqo_glue/Cargo.toml	2021-03-18 15:53:29.527861842 +0100

@@ -14,7 +14,7 @@ neqo-common = { tag = "v0.2.4", git = "h

 nserror = { path = "../../../xpcom/rust/nserror" }

 nsstring = { path = "../../../xpcom/rust/nsstring" }

 xpcom = { path = "../../../xpcom/rust/xpcom" }

-thin-vec = { version = "0.1.0", features = ["gecko-ffi"] }

+thin-vec = { version = "0.2.1", features = ["gecko-ffi"] }

 [dependencies.neqo-crypto]

 tag = "v0.2.4"

--- firefox-78.9.0/security/manager/ssl/cert_storage/Cargo.toml.D87019-thin-vec-big-endian.diff	2021-03-15 16:52:37.000000000 +0100

+++ firefox-78.9.0/security/manager/ssl/cert_storage/Cargo.toml	2021-03-18 15:53:29.528861839 +0100

@@ -18,6 +18,6 @@ rust_cascade = "0.6.0"

 sha2 = "^0.8"

 storage_variant = { path = "../../../../storage/variant" }

 tempfile = "3"

-thin-vec = { version = "0.1.0", features = ["gecko-ffi"] }

+thin-vec = { version = "0.2.1", features = ["gecko-ffi"] }

 time = "0.1"

 xpcom = { path = "../../../../xpcom/rust/xpcom" }

--- firefox-78.9.0/services/fxaccounts/rust-bridge/firefox-accounts-bridge/Cargo.toml.D87019-thin-vec-big-endian.diff	2021-03-15 16:52:38.000000000 +0100

+++ firefox-78.9.0/services/fxaccounts/rust-bridge/firefox-accounts-bridge/Cargo.toml	2021-03-18 15:53:29.528861839 +0100

@@ -20,5 +20,5 @@ nserror = { path = "../../../../xpcom/ru

 nsstring = { path = "../../../../xpcom/rust/nsstring" }

 xpcom = { path = "../../../../xpcom/rust/xpcom" }

 storage_variant = { path = "../../../../storage/variant" }

-thin-vec = { version = "0.1", features = ["gecko-ffi"] }

+thin-vec = { version = "0.2.1", features = ["gecko-ffi"] }

 fxa-client = { git = "https://github.com/mozilla/application-services", rev = "61dcc364ac0d6d0816ab88a494bbf20d824b009b", features = ["gecko"] }

--- firefox-78.9.0/services/sync/golden_gate/Cargo.toml.D87019-thin-vec-big-endian.diff	2021-03-15 16:52:38.000000000 +0100

+++ firefox-78.9.0/services/sync/golden_gate/Cargo.toml	2021-03-18 15:53:29.529861836 +0100

@@ -19,5 +19,5 @@ sync15-traits = { git = "https://github.

 xpcom = { path = "../../../xpcom/rust/xpcom" }

 [dependencies.thin-vec]

-version = "0.1.0"

+version = "0.2.1"

 features = ["gecko-ffi"]

--- firefox-78.9.0/third_party/rust/thin-vec/.cargo-checksum.json.D87019-thin-vec-big-endian.diff	2021-03-18 15:53:29.529861836 +0100

+++ firefox-78.9.0/third_party/rust/thin-vec/.cargo-checksum.json	2021-03-18 15:57:43.631168890 +0100

@@ -1 +1 @@

-{"files":{"Cargo.toml":"7b164cc8a702a204a4732cb4da2940711b8e3be915c258e2a972d4874d767b4c","README.md":"c26d7101e3031e7dd8890ce938e50cad7a1e6adf7fc2f2b0d3c36b03afe68c0b","src/lib.rs":"9f2a087cabfe0b6f83818323bb9004b45fe7548c51376816fd8d4572256bd0e8","src/range.rs":"bac59bcb6230367a39c7e28ac15263e4526f966cd8c72015873017f17c115aaa"},"package":"3a93c9ade36a827a69257925808463db46ffcf193442fad01eb9bdc1d31aed81"}

\ No newline at end of file

+{"files":{"Cargo.toml":"754c05523d17eb7591c3ea2c9294e47c05fbb257fed04b78546fb2ec7cafa8b4","README.md":"c26d7101e3031e7dd8890ce938e50cad7a1e6adf7fc2f2b0d3c36b03afe68c0b","src/lib.rs":"627c6094c3f0286dba25bc73f5672c06c5061c25b01c513d213cbdda100673a2"},"package":"dcc760ada4a9f56fc6d0e81bd143984ebc7bb1b875a6891aa2fa613ca7394fc0"}

--- firefox-78.9.0/third_party/rust/thin-vec/Cargo.toml.D87019-thin-vec-big-endian.diff	2021-03-15 16:52:42.000000000 +0100

+++ firefox-78.9.0/third_party/rust/thin-vec/Cargo.toml	2021-03-18 15:59:34.162886751 +0100

@@ -11,8 +11,9 @@

 # will likely look very different (and much more reasonable)

 [package]

+edition = "2018"

 name = "thin-vec"

-version = "0.1.2"

+version = "0.2.1"

 authors = ["Alexis Beingessner <a.beingessner@gmail.com>"]

 description = "a vec that takes up less space on the stack"

 homepage = "https://github.com/gankro/thin-vec"

--- firefox-78.9.0/third_party/rust/thin-vec/src/lib.rs.D87019-thin-vec-big-endian.diff	2021-03-15 16:52:42.000000000 +0100

+++ firefox-78.9.0/third_party/rust/thin-vec/src/lib.rs	2021-03-18 16:08:47.212871917 +0100

@@ -1,47 +1,252 @@

-mod range;

+//! ThinVec is exactly the same as Vec, except that it stores its `len` and `capacity` in the buffer

+//! it allocates.

+//!

+//! This makes the memory footprint of ThinVecs lower; notably in cases where space is reserved for

+//! a non-existence ThinVec<T>. So `Vec<ThinVec<T>>` and `Option<ThinVec<T>>::None` will waste less

+//! space. Being pointer-sized also means it can be passed/stored in registers.

+//!

+//! Of course, any actually constructed ThinVec will theoretically have a bigger allocation, but

+//! the fuzzy nature of allocators means that might not actually be the case.

+//!

+//! Properties of Vec that are preserved:

+//! * `ThinVec::new()` doesn't allocate (it points to a statically allocated singleton)

+//! * reallocation can be done in place

+//! * `size_of::<ThinVec<T>>()` == `size_of::<Option<ThinVec<T>>>()`

+//!

+//! Properties of Vec that aren't preserved:

+//! * `ThinVec<T>` can't ever be zero-cost roundtripped to a `Box<[T]>`, `String`, or `*mut T`

+//! * `from_raw_parts` doesn't exist

+//! * ThinVec currently doesn't bother to not-allocate for Zero Sized Types (e.g. `ThinVec<()>`),

+//!   but it could be done if someone cared enough to implement it.

+//!

+//!

+//!

+//! # Gecko FFI

+//!

+//! If you enable the gecko-ffi feature, ThinVec will verbatim bridge with the nsTArray type in

+//! Gecko (Firefox). That is, ThinVec and nsTArray have identical layouts *but not ABIs*, 

+//! so nsTArrays/ThinVecs an be natively manipulated by C++ and Rust, and ownership can be 

+//! transferred across the FFI boundary (**IF YOU ARE CAREFUL, SEE BELOW!!**).

+//!

+//! While this feature is handy, it is also inherently dangerous to use because Rust and C++ do not

+//! know about eachother. Specifically, this can be an issue with non-POD types (types which

+//! have destructors, move constructors, or are `!Copy`).

+//!

+//! ## Do Not Pass By Value

+//!

+//! The biggest thing to keep in mind is that **FFI functions cannot pass ThinVec/nsTArray 

+//! by-value**. That is, these are busted APIs:

+//!

+//! ```rust,ignore

+//! // BAD WRONG

+//! extern fn process_data(data: ThinVec<u32>) { ... }

+//! // BAD WRONG

+//! extern fn get_data() -> ThinVec<u32> { ... }

+//! ```

+//!

+//! You must instead pass by-reference:

+//!

+//! ```rust

+//! # use thin_vec::*;

+//! # use std::mem;

+//!

+//! // Read-only access, ok!

+//! extern fn process_data(data: &ThinVec<u32>) {

+//!     for val in data {

+//!         println!("{}", val);

+//!     }

+//! }

+//! 

+//! // Replace with empty instance to take ownership, ok!

+//! extern fn consume_data(data: &mut ThinVec<u32>) {

+//!     let owned = mem::replace(data, ThinVec::new());

+//!     mem::drop(owned);

+//! }

+//! 

+//! // Mutate input, ok!

+//! extern fn add_data(dataset: &mut ThinVec<u32>) {

+//!     dataset.push(37);

+//!     dataset.push(12);

+//! }

+//! 

+//! // Return via out-param, usually ok!

+//! //

+//! // WARNING: output must be initialized! (Empty nsTArrays are free, so just do it!)

+//! extern fn get_data(output: &mut ThinVec<u32>) {

+//!     *output = thin_vec![1, 2, 3, 4, 5];

+//! }

+//! ```

+//!

+//! Ignorable Explanation For Those Who Really Want To Know Why:

+//!

+//! > The fundamental issue is that Rust and C++ can't currently communicate about destructors, and

+//! > the semantics of C++ require destructors of function arguments to be run when the function

+//! > returns. Whether the callee or caller is responsible for this is also platform-specific, so

+//! > trying to hack around it manually would be messy. 

+//! >

+//! > Also a type having a destructor changes its C++ ABI, because that type must actually exist 

+//! > in memory (unlike a trivial struct, which is often passed in registers). We don't currently

+//! > have a way to communicate to Rust that this is happening, so even if we worked out the

+//! > destructor issue with say, MaybeUninit, it would still be a non-starter without some RFCs

+//! > to add explicit rustc support.

+//! >

+//! > Realistically, the best answer here is to have a "heavier" bindgen that can secretly

+//! > generate FFI glue so we can pass things "by value" and have it generate by-reference code

+//! > behind our back (like the cxx crate does). This would muddy up debugging/searchfox though.

+//!

+//! ## Types Should Be Trivially Relocatable

+//!

+//! Types in Rust are always trivially relocatable (unless suitably borrowed/[pinned][]/hidden).

+//! This means all Rust types are legal to relocate with a bitwise copy, you cannot provide

+//! copy or move constructors to execute when this happens, and the old location won't have its

+//! destructor run. This will cause problems for types which have a significant location

+//! (types that intrusively point into themselves or have their location registered with a service).

+//!

+//! While relocations are generally predictable if you're very careful, **you should avoid using

+//! types with significant locations with Rust FFI**.

+//!

+//! Specifically, ThinVec will trivially relocate its contents whenever it needs to reallocate its

+//! buffer to change its capacity. This is the default reallocation strategy for nsTArray, and is

+//! suitable for the vast majority of types. Just be aware of this limitation!

+//!

+//! ## Auto Arrays Are Dangerous

+//!

+//! ThinVec has *some* support for handling auto arrays which store their buffer on the stack, 

+//! but this isn't well tested.

+//!

+//! Regardless of how much support we provide, Rust won't be aware of the buffer's limited lifetime,

+//! so standard auto array safety caveats apply about returning/storing them! ThinVec won't ever

+//! produce an auto array on its own, so this is only an issue for transferring an nsTArray into

+//! Rust.

+//!

+//! ## Other Issues

+//!

+//! Standard FFI caveats also apply: 

+//!

+//!  * Rust is more strict about POD types being initialized (use MaybeUninit if you must)

+//!  * `ThinVec<T>` has no idea if the C++ version of `T` has move/copy/assign/delete overloads

+//!  * `nsTArray<T>` has no idea if the Rust version of `T` has a Drop/Clone impl

+//!  * C++ can do all sorts of unsound things that Rust can't catch

+//!  * C++ and Rust don't agree on how zero-sized/empty types should be handled

+//!

+//! The gecko-ffi feature will not work if you aren't linking with code that has nsTArray

+//! defined. Specifically, we must share the symbol for nsTArray's empty singleton. You will get

+//! linking errors if that isn't defined.

+//!

+//! The gecko-ffi feature also limits ThinVec to the legacy behaviors of nsTArray. Most notably,

+//! nsTArray has a maximum capacity of i32::MAX (~2.1 billion items). Probably not an issue.

+//! Probably.

+//!

+//! [pinned]: https://doc.rust-lang.org/std/pin/index.html

 use std::{fmt, io, ptr, mem, slice};

 use std::collections::Bound;

 use std::iter::FromIterator;

 use std::slice::IterMut;

-use std::ops::{Deref, DerefMut};

+use std::ops::{Deref, DerefMut, RangeBounds};

 use std::marker::PhantomData;

 use std::alloc::*;

 use std::cmp::*;

 use std::hash::*;

 use std::borrow::*;

-use range::RangeArgument;

 use std::ptr::NonNull;

-#[cfg(not(feature = "gecko-ffi"))]

-type SizeType = usize;

-#[cfg(feature = "gecko-ffi")]

-type SizeType = u32;

+use impl_details::*;

-#[cfg(feature = "gecko-ffi")]

-const AUTO_MASK: u32 = 1 << 31;

-#[cfg(feature = "gecko-ffi")]

-const CAP_MASK: u32 = !AUTO_MASK;

+// modules: a simple way to cfg a whole bunch of impl details at once

 #[cfg(not(feature = "gecko-ffi"))]

-const MAX_CAP: usize = !0;

-#[cfg(feature = "gecko-ffi")]

-const MAX_CAP: usize = i32::max_value() as usize;

+mod impl_details {

+    pub type SizeType = usize;

+    pub const MAX_CAP: usize = !0;

-#[cfg(not(feature = "gecko-ffi"))]

-#[inline(always)]

-fn assert_size(x: usize) -> SizeType { x }

+    #[inline(always)]

+    pub fn assert_size(x: usize) -> SizeType { x }

+}

 #[cfg(feature = "gecko-ffi")]

-#[inline]

-fn assert_size(x: usize) -> SizeType {

-    if x > MAX_CAP as usize {

-        panic!("nsTArray size may not exceed the capacity of a 32-bit sized int");

+mod impl_details {

+    // Support for briding a gecko nsTArray verbatim into a ThinVec.

+    //

+    // ThinVec can't see copy/move/delete implementations

+    // from C++

+    //

+    // The actual layout of an nsTArray is:

+    //

+    // ```cpp

+    // struct {

+    //   uint32_t mLength;

+    //   uint32_t mCapacity: 31;

+    //   uint32_t mIsAutoArray: 1;

+    // }

+    // ```

+    //

+    // Rust doesn't natively support bit-fields, so we manually mask

+    // and shift the bit. When the "auto" bit is set, the header and buffer

+    // are actually on the stack, meaning the ThinVec pointer-to-header

+    // is essentially an "owned borrow", and therefore dangerous to handle.

+    // There are no safety guards for this situation.

+    //

+    // On little-endian platforms, the auto bit will be the high-bit of

+    // our capacity u32. On big-endian platforms, it will be the low bit.

+    // Hence we need some platform-specific CFGs for the necessary masking/shifting.

+    // 

+    // ThinVec won't ever construct an auto array. They only happen when

+    // bridging from C++. This means we don't need to ever set/preserve the bit.

+    // We just need to be able to read and handle it if it happens to be there.

+    //

+    // Handling the auto bit mostly just means not freeing/reallocating the buffer.

+

+    pub type SizeType = u32;

+

+    pub const MAX_CAP: usize = i32::max_value() as usize;

+

+    // Little endian: the auto bit is the high bit, and the capacity is

+    // verbatim. So we just need to mask off the high bit. Note that

+    // this masking is unnecessary when packing, because assert_size

+    // guards against the high bit being set.

+    #[cfg(target_endian = "little")]

+    pub fn pack_capacity(cap: SizeType) -> SizeType {

+        cap as SizeType

+    }

+    #[cfg(target_endian = "little")]

+    pub fn unpack_capacity(cap: SizeType) -> usize {

+        (cap as usize) & !(1 << 31)

+    }

+    #[cfg(target_endian = "little")]

+    pub fn is_auto(cap: SizeType) -> bool {

+        (cap & (1 << 31)) != 0

+    }

+

+    // Big endian: the auto bit is the low bit, and the capacity is

+    // shifted up one bit. Masking out the auto bit is unnecessary,

+    // as rust shifts always shift in 0's for unsigned integers.

+    #[cfg(target_endian = "big")]

+    pub fn pack_capacity(cap: SizeType) -> SizeType {

+        (cap as SizeType) << 1

+    }

+    #[cfg(target_endian = "big")]

+    pub fn unpack_capacity(cap: SizeType) -> usize {

+        (cap >> 1) as usize

+    }

+    #[cfg(target_endian = "big")]

+    pub fn is_auto(cap: SizeType) -> bool {

+        (cap & 1) != 0

     }

-    x as SizeType

+

+    #[inline]

+    pub fn assert_size(x: usize) -> SizeType {

+        if x > MAX_CAP as usize {

+            panic!("nsTArray size may not exceed the capacity of a 32-bit sized int");

+        }

+        x as SizeType

+    }

+

 }

-/// The header of a ThinVec

+/// The header of a ThinVec.

+///

+/// The _cap can be a bitfield, so use accessors to avoid trouble.

 #[repr(C)]

 struct Header {

     _len: SizeType,

@@ -53,38 +258,10 @@ impl Header {

         self._len as usize

     }

-    #[cfg(feature = "gecko-ffi")]

-    fn cap(&self) -> usize {

-        (self._cap & CAP_MASK) as usize

-    }

-

-    #[cfg(not(feature = "gecko-ffi"))]

-    fn cap(&self) -> usize {

-        self._cap as usize

-    }

-

     fn set_len(&mut self, len: usize) {

         self._len = assert_size(len);

     }

-    #[cfg(feature = "gecko-ffi")]

-    fn set_cap(&mut self, cap: usize) {

-        debug_assert!(cap & (CAP_MASK as usize) == cap);

-        // FIXME: this is busted because it reads uninit memory

-        // debug_assert!(!self.uses_stack_allocated_buffer());

-        self._cap = assert_size(cap) & CAP_MASK;

-    }

-

-    #[cfg(feature = "gecko-ffi")]

-    fn uses_stack_allocated_buffer(&self) -> bool {

-        self._cap & AUTO_MASK != 0

-    }

-

-    #[cfg(not(feature = "gecko-ffi"))]

-    fn set_cap(&mut self, cap: usize) {

-        self._cap = assert_size(cap);

-    }

-

     fn data<T>(&self) -> *mut T {

         let header_size = mem::size_of::<Header>();

         let padding = padding::<T>();

@@ -102,6 +279,41 @@ impl Header {

     }

 }

+

+#[cfg(feature = "gecko-ffi")]

+impl Header {

+    fn cap(&self) -> usize {

+        unpack_capacity(self._cap)

+    }

+

+    fn set_cap(&mut self, cap: usize) {

+        // debug check that our packing is working

+        debug_assert_eq!(unpack_capacity(pack_capacity(cap as SizeType)), cap);

+        // FIXME: this assert is busted because it reads uninit memory

+        // debug_assert!(!self.uses_stack_allocated_buffer());

+

+        // NOTE: this always stores a cleared auto bit, because set_cap

+        // is only invoked by Rust, and Rust doesn't create auto arrays.

+        self._cap = pack_capacity(assert_size(cap));

+    }

+

+    fn uses_stack_allocated_buffer(&self) -> bool {

+        is_auto(self._cap)

+    }

+}

+

+#[cfg(not(feature = "gecko-ffi"))]

+impl Header {

+    fn cap(&self) -> usize {

+        self._cap as usize

+    }

+

+    fn set_cap(&mut self, cap: usize) {

+        self._cap = assert_size(cap);

+    }

+}

+

+

 /// Singleton that all empty collections share.

 /// Note: can't store non-zero ZSTs, we allocate in that case. We could

 /// optimize everything to not do that (basically, make ptr == len and branch

@@ -118,9 +330,7 @@ extern {

 // TODO: overflow checks everywhere

-// Utils

-

-fn oom() -> ! { std::process::abort() }

+// Utils for computing layouts of allocations

 fn alloc_size<T>(cap: usize) -> usize {

     // Compute "real" header size with pointer math

@@ -165,9 +375,10 @@ fn layout<T>(cap: usize) -> Layout {

 fn header_with_capacity<T>(cap: usize) -> NonNull<Header> {

     debug_assert!(cap > 0);

     unsafe {

-        let header = alloc(layout::<T>(cap)) as *mut Header;

+        let layout = layout::<T>(cap);

+        let header = alloc(layout) as *mut Header;

-        if header.is_null() { oom() }

+        if header.is_null() { handle_alloc_error(layout) }

         // "Infinite" capacity for zero-sized types:

         (*header).set_cap(if mem::size_of::<T>() == 0 { MAX_CAP } else { cap });

@@ -179,28 +390,8 @@ fn header_with_capacity<T>(cap: usize) -

-/// ThinVec is exactly the same as Vec, except that it stores its `len` and `capacity` in the buffer

-/// it allocates.

-///

-/// This makes the memory footprint of ThinVecs lower; notably in cases where space is reserved for

-/// a non-existence ThinVec<T>. So `Vec<ThinVec<T>>` and `Option<ThinVec<T>>::None` will waste less

-/// space. Being pointer-sized also means it can be passed/stored in registers.

-///

-/// Of course, any actually constructed ThinVec will theoretically have a bigger allocation, but

-/// the fuzzy nature of allocators means that might not actually be the case.

-///

-/// Properties of Vec that are preserved:

-/// * `ThinVec::new()` doesn't allocate (it points to a statically allocated singleton)

-/// * reallocation can be done in place

-/// * `size_of::<ThinVec<T>>()` == `size_of::<Option<ThinVec<T>>>()`

-///   * NOTE: This is only possible when the `unstable` feature is used.

-///

-/// Properties of Vec that aren't preserved:

-/// * `ThinVec<T>` can't ever be zero-cost roundtripped to a `Box<[T]>`, `String`, or `*mut T`

-/// * `from_raw_parts` doesn't exist

-/// * ThinVec currently doesn't bother to not-allocate for Zero Sized Types (e.g. `ThinVec<()>`),

-///   but it could be done if someone cared enough to implement it.

-#[cfg_attr(feature = "gecko-ffi", repr(C))]

+/// See the crate's top level documentation for a description of this type.

+#[repr(C)]

 pub struct ThinVec<T> {

     ptr: NonNull<Header>,

     boo: PhantomData<T>,

@@ -630,15 +821,15 @@ impl<T> ThinVec<T> {

     }

     pub fn drain<R>(&mut self, range: R) -> Drain<T>

-        where R: RangeArgument<usize>

+        where R: RangeBounds<usize>

     {

         let len = self.len();

-        let start = match range.start() {

+        let start = match range.start_bound() {

             Bound::Included(&n) => n,

             Bound::Excluded(&n) => n + 1,

             Bound::Unbounded => 0,

         };

-        let end = match range.end() {

+        let end = match range.end_bound() {

             Bound::Included(&n) => n + 1,

             Bound::Excluded(&n) => n,

             Bound::Unbounded => len,

@@ -688,11 +879,30 @@ impl<T> ThinVec<T> {

                 alloc_size::<T>(new_cap),

             ) as *mut Header;

-            if ptr.is_null() { oom() }

+            if ptr.is_null() { handle_alloc_error(layout::<T>(new_cap)) }

             (*ptr).set_cap(new_cap);

             self.ptr = NonNull::new_unchecked(ptr);

         } else {

-            self.ptr = header_with_capacity::<T>(new_cap);

+            let mut new_header = header_with_capacity::<T>(new_cap);

+

+            // If we get here and have a non-zero len, then we must be handling

+            // a gecko auto array, and we have items in a stack buffer. We shouldn't

+            // free it, but we should memcopy the contents out of it and mark it as empty.

+            //

+            // T is assumed to be trivially relocatable, as this is ~required

+            // for Rust compatibility anyway. Furthermore, we assume C++ won't try

+            // to unconditionally destroy the contents of the stack allocated buffer

+            // (i.e. it's obfuscated behind a union).

+            //

+            // In effect, we are partially reimplementing the auto array move constructor

+            // by leaving behind a valid empty instance.

+            let len = self.len();

+            if cfg!(feature = "gecko-ffi") && len > 0 {

+                new_header.as_mut().data::<T>().copy_from_nonoverlapping(self.data_raw(), len);

+                self.set_len(0);

+            }

+            

+            self.ptr = new_header;

         }

     }

@@ -1093,10 +1303,7 @@ mod tests {

         use std::mem::size_of;

         assert_eq!(size_of::<ThinVec<u8>>(), size_of::<&u8>());

-        // We don't perform the null-pointer optimization on stable rust.

-        if cfg!(feature = "unstable") {

-            assert_eq!(size_of::<Option<ThinVec<u8>>>(), size_of::<&u8>());

-        }

+        assert_eq!(size_of::<Option<ThinVec<u8>>>(), size_of::<&u8>());

     }

     #[test]

@@ -1731,7 +1938,6 @@ mod std_tests {

         assert_eq!(v, &[(), ()]);

     }

-/* TODO: support inclusive ranges

     #[test]

     fn test_drain_inclusive_range() {

         let mut v = thin_vec!['a', 'b', 'c', 'd', 'e'];

@@ -1761,6 +1967,7 @@ mod std_tests {

     }

     #[test]

+    #[cfg(not(feature = "gecko-ffi"))]

     fn test_drain_max_vec_size() {

         let mut v = ThinVec::<()>::with_capacity(usize::max_value());

         unsafe { v.set_len(usize::max_value()); }

@@ -1781,7 +1988,6 @@ mod std_tests {

         let mut v = thin_vec![1, 2, 3, 4, 5];

         v.drain(5..=5);

     }

-*/

 /* TODO: implement splice?

     #[test]

@@ -2187,7 +2393,7 @@ mod std_tests {

         assert!(v.capacity() >= 33)

     }

-/* TODO: implement try_reserve 

+/* TODO: implement try_reserve

     #[test]

     fn test_try_reserve() {

--- firefox-78.9.0/toolkit/components/cascade_bloom_filter/Cargo.toml.D87019-thin-vec-big-endian.diff	2021-03-15 16:52:42.000000000 +0100

+++ firefox-78.9.0/toolkit/components/cascade_bloom_filter/Cargo.toml	2021-03-18 15:54:35.137670977 +0100

@@ -8,5 +8,5 @@ nserror = { path = "../../../xpcom/rust/

 nsstring = { path = "../../../xpcom/rust/nsstring" }

 rental = "0.5.5"

 rust_cascade = "0.6.0"

-thin-vec = { version = "0.1.0", features = ["gecko-ffi"] }

+thin-vec = { version = "0.2.1", features = ["gecko-ffi"] }

 xpcom = { path = "../../../xpcom/rust/xpcom" }

--- firefox-78.9.0/toolkit/components/extensions/storage/webext_storage_bridge/Cargo.toml.D87019-thin-vec-big-endian.diff	2021-03-15 16:52:42.000000000 +0100

+++ firefox-78.9.0/toolkit/components/extensions/storage/webext_storage_bridge/Cargo.toml	2021-03-18 15:54:35.139670971 +0100

@@ -13,7 +13,7 @@ moz_task = { path = "../../../../../xpco

 nserror = { path = "../../../../../xpcom/rust/nserror" }

 nsstring = { path = "../../../../../xpcom/rust/nsstring" }

 once_cell = "1"

-thin-vec = { version = "0.1.0", features = ["gecko-ffi"] }

+thin-vec = { version = "0.2.1", features = ["gecko-ffi"] }

 xpcom = { path = "../../../../../xpcom/rust/xpcom" }

 serde = "1"

 serde_json = "1"

--- firefox-78.9.0/toolkit/components/kvstore/Cargo.toml.D87019-thin-vec-big-endian.diff	2021-03-15 16:52:42.000000000 +0100

+++ firefox-78.9.0/toolkit/components/kvstore/Cargo.toml	2021-03-18 15:54:35.141670966 +0100

@@ -18,7 +18,7 @@ rkv = "0.10.2"

 storage_variant = { path = "../../../storage/variant" }

 xpcom = { path = "../../../xpcom/rust/xpcom" }

 tempfile = "3"

-thin-vec = { version = "0.1.0", features = ["gecko-ffi"] }

+thin-vec = { version = "0.2.1", features = ["gecko-ffi"] }

 # Get rid of failure's dependency on backtrace. Eventually

 # backtrace will move into Rust core, but we don't need it here.

--- firefox-78.9.0/toolkit/components/places/bookmark_sync/Cargo.toml.D87019-thin-vec-big-endian.diff	2021-03-15 16:52:42.000000000 +0100

+++ firefox-78.9.0/toolkit/components/places/bookmark_sync/Cargo.toml	2021-03-18 15:54:35.142670963 +0100

@@ -19,5 +19,5 @@ url = "2.0"

 xpcom = { path = "../../../../xpcom/rust/xpcom" }

 [dependencies.thin-vec]

-version = "0.1.0"

+version = "0.2.1"

 features = ["gecko-ffi"]

--- firefox-78.9.0/tools/profiler/rust-helper/Cargo.toml.D87019-thin-vec-big-endian.diff	2021-03-15 16:52:42.000000000 +0100

+++ firefox-78.9.0/tools/profiler/rust-helper/Cargo.toml	2021-03-18 15:54:35.143670960 +0100

@@ -23,7 +23,7 @@ features = ["endian_fd", "elf32", "elf64

 default-features = false

 [dependencies.thin-vec]

-version = "0.1.0"

+version = "0.2.1"

 features = ["gecko-ffi"]

 [features]

--- firefox-78.9.0/xpcom/rust/xpcom/Cargo.toml.D87019-thin-vec-big-endian.diff	2021-03-15 16:52:43.000000000 +0100

+++ firefox-78.9.0/xpcom/rust/xpcom/Cargo.toml	2021-03-18 15:54:35.149670942 +0100

@@ -9,4 +9,4 @@ nsstring = { path = "../nsstring" }

 nserror = { path = "../nserror" }

 threadbound = "0.1"

 xpcom_macros = { path = "xpcom_macros" }

-thin-vec = { version = "0.1.0", features = ["gecko-ffi"] }

+thin-vec = { version = "0.2.1", features = ["gecko-ffi"] }