Add comment to patch.
Changes in 2.2.5 (since 2.2.4):
* Notable improvements
** Greatly improved performance of bidirectional pipes.
The performance of bidirectional pipes, as created using 'open-pipe' or
'open-pipe*' in OPEN_BOTH mode, has been greatly improved. When reading
large blocks of binary data from a bidirectional pipe, the maximum
bandwidth has been increased by a factor of ~10^3 in some cases.
** New 'get-bytevector-some!' I/O primitive.
This new I/O primitive is similar to 'get-bytevector-some' from the
R6RS, except that it writes its data to a user-specified range of
indices in an existing bytevector. As a corollary, it is also now
possible to specify a maximum number of bytes to read. Note that
'get-bytevector-some', and now 'get-bytevector-some!', are unique among
Guile's I/O primitives in their support of efficient binary reads of
potentially large blocks while also allowing for short reads, to avoid
undesired blocking. Now these operations can be performed while also
avoiding heap-allocation.
'get-bytevector-some!' is needed to efficiently implement the new
bidirectional pipes, which are built upon R6RS custom binary
input/output ports.
** get-bytevector-{n!,some,some!} now support suspendable I/O.
Scheme implementations of 'get-bytevector-n!', 'get-bytevector-some',
and 'get-bytevector-some!' have been added to (ice-9 suspendable-ports).
As a result, these I/O operations now support suspendable I/O.
* Compiler improvements
** guild compile: Add -Wshadowed-toplevel.
Top-level definitions that shadow previous top-level definitions from
the same compilation unit will now trigger a compile-time warning, if
-Wshadowed-toplevel is enabled. It is enabled by default.
** guild compile: Add '-x' flag.
Passing "-x EXT" to 'guild compile' will now cause EXT to be recognized
as a valid source file name extension. For example, to compile R6RS
code, you might want to pass "-x .sls" so that files ending in ".sls"
can be found.
* Miscellaneous improvements
** Bootstrap optimization
eval.go and psyntax-pp.go are now built before the rest of the .go files
so that they are processed by a fast macro expander. This saves time
when using parallel builds.
** put-u8 now always writes a single byte, regardless of the port encoding.
Previously, (put-u8 PORT OCTET) worked as expected only when writing to
binary ports, i.e. those with port encoding "ISO-8859-1" a.k.a. Latin-1.
Strictly speaking, this meets the requirements of the R6RS 'put-u8',
which need only support binary ports. However, Guile in fact allows
binary I/O to be performed on any port, and yet 'put-u8' behaved in a
surprising way with other port encodings: it would perform a _textual_
I/O operation, writing the character with Unicode scalar value OCTET.
Now, 'put-u8' always writes a single byte with value OCTET, regardless
of the port encoding.
** Optimize fixnum exact integer square roots.
'exact-integer-sqrt' now avoids heap allocation when applied to a
fixnum. 'sqrt' now avoids heap allocation when applied to a fixnum
that's a perfect square. Fewer heap allocations are now required when
applying 'sqrt' to a square of an exact rational whose numerator or
denominator are fixnums.
** scm_mkstrport: Optimize the POS -> BYTE_POS conversion.
scm_mkstrport now avoids an unnecessary heap allocation and conversion
to UTF-8, when STR is provided and POS is non-zero.
** SRFI-19: Support ~N in string->date.
Support for the ~N escape, which allows fractions of a second to be
parsed, is now supported in SRFI-19 'string->date'.
** SRFI-19: Update the leap second table.
The leap on 1 January 2017 was added to SRFI-19's leap second table.
** stexi->shtml: Add support for @i, @math, @tie and @dots.
stexi->shtml is now able to convert @i, @math, @tie and @dots to HTML.
** Define AT_SYMLINK_NOFOLLOW, AT_NO_AUTOMOUNT, and AT_EMPTY_PATH.
AT_SYMLINK_FOLLOW, AT_NO_AUTOMOUNT, and AT_EMPTY_PATH are now available
from Scheme, if supported on the platform.
** Improvements to the 'time' macro from (ice-9 time).
The 'time' macro now supports expressions that return multiple values.
It has also been rewritten as a hygienic 'syntax-rules' macro.
Previously, it was built using 'define-macro', and was therefore
unhygienic. This is not merely an internal implementation detail, but
is potentially relevant to any user of the 'time' macro, since it could
lead to unintended variable capture and other problems.
** Clarify the documentation for 'nil?'.
See commit b44f505f1571fc9c42e58982f161a9cfc81fb7f4.
** Clarify the manual's "Processes" section.
See commit 8cdd3a0773930ca872a13aada7a1344f03bb382b.
** Avoid 'with-latin1-locale' in binary I/O tests.
See commit 162a031e5f2c64cd23fcf069fb7b5071196f9527.
** Update user-visible copyright years.
* Bug fixes
** Avoid regexp ranges in HTTP inter-protocol exploitation check.
The regular expression used to check for HTTP inter-protocol
exploitation attacks previously used a character range '0-9', whose
meaning depends on the current locale. This has now been fixed.
** Fixes to the SRFI-19 time/date library.
*** TAI-to-UTC conversion leaps at the wrong time.
<https://bugs.gnu.org/21911>
*** time-utc->date shows bogus zone-dependent leap second.
<https://bugs.gnu.org/22034>
*** Manual incorrectly describes Julian Date.
<https://bugs.gnu.org/21902>
*** date->string duff ISO 8601 negative years.
<https://bugs.gnu.org/21903>
*** date->string duff ISO 8601 format for non-4-digit years.
<https://bugs.gnu.org/21904>
*** julian-day->date negative input breakage.
<https://bugs.gnu.org/21906>
*** time-duration screws up negative durations.
<https://bugs.gnu.org/26162>
*** time-difference doesn't detect error of differing time types.
<https://bugs.gnu.org/26163>
** Improve overflow checks in bytevector, string, and I/O operations.
Several numerical computations, performed using primitive C arithmetic
in Guile's core bytevector, string, and I/O operations, have been
rewritten to avoid overflows.
** Fix type inferencing for 'nil?' and 'null?' predicates.
Previously, the compiler would sometimes miscompile certain combinations
of 'nil?' and 'null?' predicates present within the same top-level form.
See <https://bugs.gnu.org/33036>.
** Fix 'atomic-box-compare-and-swap!'.
Previously, 'atomic-box-compare-and-swap!' would sometimes spuriously
fail on architectures based on Load-Linked/Store-Conditional (LL/SC)
synchronication primitives (e.g. ARM, PowerPC, and MIPS) in a way that
was undetectable by the caller. See <https://bugs.gnu.org/32786>.
** Make URI handling locale independent.
Previously, procedures in (web uri) would misbehave in some locales
including sv_SE. See <https://bugs.gnu.org/35785>.
** Strings, i18n: Limit the use of alloca to approximately 8 kilobytes.
Previously, 'string-locale-ci=?', 'string-locale-ci<?',
'string-locale<?', 'string-locale-{downcase,upcase,titlecase}' and
'string-normalize-{nfd,nfc,nfkd,nfkc}' would overflow the C stack when
applied to very large strings.
** Fix documentation of R6RS 'binary-port?' to reflect reality.
Previously, the documentation incorrectly stated that 'binary-port?'
always returns #t. In fact, it returns #t if and only if the port
encoding is "ISO-8859-1". The documentation for 'binary-port?' and
'textual-port?' has been rewritten to reflect the current reality, and
also to leave open the possibility of changing the behavior of these
predicates in a future version of Guile.
** Avoid passing NULL to 'memcpy' and 'memcmp'.
Previously, NULL was sometimes passed to 'memcpy' or 'memcmp' when the
size argument was 0.
** Save and restore errno in the signal handler.
Previously, Guile's synchronous C signal handler failed to save and
restore 'errno', although it might change its value. This could
potentially lead to spurious corruptions of 'errno' within threads
interrupted by signals.
** scm_to_stringn: Avoid passing NULL to c_strcasecmp.
<https://lists.gnu.org/archive/html/guile-user/2019-05/msg00070.html>
** r6rs-ports: Accept 'port-position' values greater than 2^32.
<https://bugs.gnu.org/32161>
** r6rs-ports: 'put-bytevector' accepts 64-bit integers.
Fixed in commit 741c45458da0831a12a4f8d729814bf9f2cb6571.
** Fix R6RS call-with-{input,output}-file to open textual ports.
<https://bugs.gnu.org/32329>
** Update (ice-9 match) to include selected bug fixes from upstream.
*** ice-9/match named match-let is not working
<https://bugs.gnu.org/22925>
** open-process: Fix dup(2) and execvp(2) error handling.
Fixed in commit 521f1ab4709217407496004019c00005d2a82f78.
** bytevectors: Support large indices in integer accessors.
Fixed in commit b9cf3517efd4643670d970d2692bc7bede9a85e8.
** bytevectors: Fix list validation of *list->bytevector procedures.
<https://bugs.gnu.org/32938>
** Gracefully handle huge shift counts in 'ash' and 'round-ash'.
<https://bugs.gnu.org/32644>
** In 'ash' and 'round-ash', handle right shift count of LONG_MIN.
<https://bugs.gnu.org/21901>
** Use 'scm_from_utf8_{string,symbol,keyword}' for C string literals.
<https://bugs.gnu.org/33044>
** web: Add support for HTTP header continuation lines.
Fixed in commit 73cde5ed7218a090ecee888870908af5445796f0.
** scm_seed_to_random_state: Support wide string arguments.
<https://bugs.gnu.org/33044>
** Do not warn the user when 'madvise' returns ENOSYS.
Fixed in commit 45e4ace6603e00b297e6542362273041aebe7305.
** Add 'texinfo' as a dependency in the README.
Fixed in commit 1bbce71501198c3c7abdf07941f5cdc1434858c2.
** Don't mutate read-only string in ports test.
Fixed in commit 552f007e91a97f136aad1b22918688b61d03a4a3.
** Remove redefinition of when & unless in snarf-check-and-output-texi.
Fixed in commit 1ba5d6f47a54dceee4452a1e7726d2635e5b3449.
** Fix strftime when Guile is built without threading support.
Fixed in commit 139c702fc8b61fdeb813c3428fef3701ea8677f9.
** Avoid leaking a file descriptor in test-unwind.
Fixed in commit 1437b76777e576b3d000e2f80c5ecdb33a74ac33.
** Fix binary output on files created by mkstemp!.
Fixed in commit 78468baa118d316050a27e43250966e52ffd3d54.
** Fix crypt-on-glibc test error.
Fixed in commit 27ffbfb0235de466016ea5a6421508f6548971b6.
** Fix race when expanding syntax-parameterize and define-syntax-parameter.
<https://bugs.gnu.org/27476#102>
** Add a fallback value for the locale-monetary-decimal-point.
Fixed in commit 9ba449643d4c2ac1d2174befca7d765af222bcc0.
** Handle newlib C library's langinfo constant names.
Fixed in commit 92105d13ad1363b511214589b7d62d95304beb17.
** Make locale monetary conversion tests be less strict on terminal whitespace.
Fixed in commit 2a3ccfb66714efc1c081ea6e921336f80b756d3c.
** Disable test for current value of setitimer on Cygwin.
Fixed in commit 3a64c504caaf83e9faf2ec9b7d0e031e1a6a09b9.
** Fix gc.test "after-gc-hook gets called" failures.
<https://bugs.gnu.org/31776#17>
** Update iconv.m4 from gnulib, to fix an iconv leak during configure.
<https://lists.gnu.org/archive/html/guile-devel/2019-05/msg00011.html>
** guild compile: Add missing newline in "unrecognized option" error message.
Fixed in commit 85c5bae4fd94f8686d26fd792b7c0f588c23bd94.
** 'basename' now correctly handles "/" and "//".
Fixed in commit 36ad1d24b3d2c174a64c445502a36f19605dbd65.
** Make srfi-71 visible through 'cond-expand'.
Fixed in commit 59a06d8392234fbec8b3605cec266a7a0a7b7a56.
5c339e601b