Commit c3d01b0f authored by Henri Sivonen's avatar Henri Sivonen
Browse files

Bug 1484045 - Prohibit shrinking of the string's buffer in appends of Latin1... 

Bug 1484045 - Prohibit shrinking of the string's buffer in appends of Latin1 to UTF-16 and vice versa. r=froydnj

This restores the old allocation semantics for "append" operations between
Latin1 and UTF-16 while keeping the buffer re-use optimization for the
"assign" cases.

MozReview-Commit-ID: 8JCw3AaCNLN

Differential Revision: https://phabricator.services.mozilla.com/D3582

--HG--
extra : moz-landing-system : lando
parent 569510fb

servo/support/gecko/nsstring/src/conversions.rs

+14 −12
Original line number Diff line number Diff line
@@ -139,10 +139,10 @@ macro_rules! constant_conversion { 
    (name = $name:ident,

     convert = $convert:ident,

     other_ty = $other_ty:ty) => (

        fn $name(&mut self, other: $other_ty, old_len: usize) -> Result<BulkWriteOk, ()> {

        fn $name(&mut self, other: $other_ty, old_len: usize, allow_shrinking: bool) -> Result<BulkWriteOk, ()> {

            let new_len = old_len.checked_add(other.len()).ok_or(())?;

            let mut handle = unsafe {

                self.bulk_write(new_len, old_len, true)?

                self.bulk_write(new_len, old_len, allow_shrinking)?

            };

            $convert(other, &mut handle.as_mut_slice()[old_len..]);

            Ok(handle.finish(new_len, false))
@@ -281,7 +281,7 @@ impl nsAString { 
    /// Convert a Latin1 (i.e. byte value equals scalar value; not windows-1252!)

    /// into UTF-16 and replace the content of this string with the conversion result.

    pub fn assign_latin1(&mut self, other: &[u8]) {

        self.fallible_append_latin1_impl(other, 0)

        self.fallible_append_latin1_impl(other, 0, true)

            .expect("Out of memory");

    }
@@ -289,14 +289,14 @@ impl nsAString { 
    /// into UTF-16 and fallibly replace the content of this string with the

    /// conversion result.

    pub fn fallible_assign_latin1(&mut self, other: &[u8]) -> Result<(), ()> {

        self.fallible_append_latin1_impl(other, 0).map(|_| ())

        self.fallible_append_latin1_impl(other, 0, true).map(|_| ())

    }



    /// Convert a Latin1 (i.e. byte value equals scalar value; not windows-1252!)

    /// into UTF-16 and append the conversion result to this string.

    pub fn append_latin1(&mut self, other: &[u8]) {

        let len = self.len();

        self.fallible_append_latin1_impl(other, len)

        self.fallible_append_latin1_impl(other, len, false)

            .expect("Out of memory");

    }
@@ -304,7 +304,7 @@ impl nsAString { 
    /// into UTF-16 and fallibly append the conversion result to this string.

    pub fn fallible_append_latin1(&mut self, other: &[u8]) -> Result<(), ()> {

        let len = self.len();

        self.fallible_append_latin1_impl(other, len).map(|_| ())

        self.fallible_append_latin1_impl(other, len, false).map(|_| ())

    }

}
@@ -415,7 +415,7 @@ impl nsACString { 
    /// release builds. The nature of the garbage may differ based on CPU

    /// architecture and must not be relied upon.

    pub fn assign_utf16_to_latin1_lossy(&mut self, other: &[u16]) {

        self.fallible_append_utf16_to_latin1_lossy_impl(other, 0)

        self.fallible_append_utf16_to_latin1_lossy_impl(other, 0, true)

            .expect("Out of memory");

    }
@@ -430,7 +430,7 @@ impl nsACString { 
    /// release builds. The nature of the garbage may differ based on CPU

    /// architecture and must not be relied upon.

    pub fn fallible_assign_utf16_to_latin1_lossy(&mut self, other: &[u16]) -> Result<(), ()> {

        self.fallible_append_utf16_to_latin1_lossy_impl(other, 0)

        self.fallible_append_utf16_to_latin1_lossy_impl(other, 0, true)

            .map(|_| ())

    }
@@ -446,7 +446,7 @@ impl nsACString { 
    /// architecture and must not be relied upon.

    pub fn append_utf16_to_latin1_lossy(&mut self, other: &[u16]) {

        let len = self.len();

        self.fallible_append_utf16_to_latin1_lossy_impl(other, len)

        self.fallible_append_utf16_to_latin1_lossy_impl(other, len, false)

            .expect("Out of memory");

    }
@@ -462,7 +462,7 @@ impl nsACString { 
    /// architecture and must not be relied upon.

    pub fn fallible_append_utf16_to_latin1_lossy(&mut self, other: &[u16]) -> Result<(), ()> {

        let len = self.len();

        self.fallible_append_utf16_to_latin1_lossy_impl(other, len)

        self.fallible_append_utf16_to_latin1_lossy_impl(other, len, false)

            .map(|_| ())

    }
@@ -692,10 +692,11 @@ pub unsafe extern "C" fn nsstring_fallible_append_latin1_impl( 
    other: *const u8,

    other_len: usize,

    old_len: usize,

    allow_shrinking: bool,

) -> bool {

    let other_slice = slice::from_raw_parts(other, other_len);

    (*this)

        .fallible_append_latin1_impl(other_slice, old_len)

        .fallible_append_latin1_impl(other_slice, old_len, allow_shrinking)

        .is_ok()

}
@@ -718,10 +719,11 @@ pub unsafe extern "C" fn nscstring_fallible_append_utf16_to_latin1_lossy_impl( 
    other: *const u16,

    other_len: usize,

    old_len: usize,

    allow_shrinking: bool,

) -> bool {

    let other_slice = slice::from_raw_parts(other, other_len);

    (*this)

        .fallible_append_utf16_to_latin1_lossy_impl(other_slice, old_len)

        .fallible_append_utf16_to_latin1_lossy_impl(other_slice, old_len, allow_shrinking)

        .is_ok()

}

xpcom/string/nsReadableUtils.h

+8 −6
Original line number Diff line number Diff line
@@ -88,7 +88,8 @@ extern "C" { 
  nsstring_fallible_append_latin1_impl(nsAString* aThis,

                                       const char* aOther,

                                       size_t aOtherLen,

                                       size_t aOldLen);

                                       size_t aOldLen,

                                       bool aAllowShrinking);



  bool

  nscstring_fallible_append_utf16_to_utf8_impl(nsACString* aThis,
@@ -100,7 +101,8 @@ extern "C" { 
  nscstring_fallible_append_utf16_to_latin1_lossy_impl(nsACString* aThis,

                                                       const char16_t*,

                                                       size_t aOtherLen,

                                                       size_t aOldLen);

                                                       size_t aOldLen,

                                                       bool aAllowShrinking);



  bool

  nscstring_fallible_append_utf8_to_latin1_lossy_check(nsACString* aThis,
@@ -256,7 +258,7 @@ CopyASCIItoUTF16(mozilla::Span<const char> aSource, 
                 const mozilla::fallible_t&)

{

  return nsstring_fallible_append_latin1_impl(

    &aDest, aSource.Elements(), aSource.Length(), 0);

    &aDest, aSource.Elements(), aSource.Length(), 0, true);

}



inline void
@@ -273,7 +275,7 @@ AppendASCIItoUTF16(mozilla::Span<const char> aSource, 
                   const mozilla::fallible_t&)

{

  return nsstring_fallible_append_latin1_impl(

    &aDest, aSource.Elements(), aSource.Length(), aDest.Length());

    &aDest, aSource.Elements(), aSource.Length(), aDest.Length(), false);

}



inline void
@@ -335,7 +337,7 @@ LossyCopyUTF16toASCII(mozilla::Span<const char16_t> aSource, 
                      const mozilla::fallible_t&)

{

  return nscstring_fallible_append_utf16_to_latin1_lossy_impl(

    &aDest, aSource.Elements(), aSource.Length(), 0);

    &aDest, aSource.Elements(), aSource.Length(), 0, true);

}



inline void
@@ -352,7 +354,7 @@ LossyAppendUTF16toASCII(mozilla::Span<const char16_t> aSource, 
                        const mozilla::fallible_t&)

{

  return nscstring_fallible_append_utf16_to_latin1_lossy_impl(

    &aDest, aSource.Elements(), aSource.Length(), aDest.Length());

    &aDest, aSource.Elements(), aSource.Length(), aDest.Length(), false);

}



inline void