app-shells/zsh: Revbump to fix performance regression

which was introduced with previous regression fix.

Closes: https://bugs.gentoo.org/839900
Signed-off-by: Lars Wendler <polynomial-c@gentoo.org>

2 files changed, 140 insertions, 0 deletions

diff --git a/app-shells/zsh/files/zsh-5.8.1-performance_regression_fix.patch b/app-shells/zsh/files/zsh-5.8.1-performance_regression_fix.patch
new file mode 100644
index 000000000000..14a3f38eb96d
--- /dev/null
+++ b/app-shells/zsh/files/zsh-5.8.1-performance_regression_fix.patch
@@ -0,0 +1,139 @@
+From cbe8d2bcdc20682464217856aa48628804637f28 Mon Sep 17 00:00:00 2001
+From: Bart Schaefer <schaefer@zsh.org>
+Date: Thu, 28 Apr 2022 21:06:51 -0700
+Subject: [PATCH] 50133: use read-ahead and lseek-rewind for efficient
+ line-buffered input
+
+---
+ ChangeLog    |  6 ++++++
+ Src/input.c  | 24 ++++++++++++++++++++-
+ configure.ac | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++++
+ 3 files changed, 88 insertions(+), 1 deletion(-)
+
+diff --git a/ChangeLog b/ChangeLog
+index cae2fc4e3..79c77741b 100644
+--- a/ChangeLog
++++ b/ChangeLog
+@@ -1,3 +1,9 @@
++2022-04-28  Bart Schaefer  <schaefer@zsh.org>
++
++	* 50133 (Bart, PWS, Jun-ichi): Src/input.c, configure.ac: when
++	lseek(2) is available, use it to check for and rewind read-ahead
++	for more efficient line-buffered input.
++
+ 2022-03-03  Peter Stephenson  <p.w.stephenson@ntlworld.com>
+ 
+ 	* 49792: Src/input.c, Test/A01grammar.ztst: Use line buffering
+diff --git a/Src/input.c b/Src/input.c
+index caa8e23b0..6cc1b8a51 100644
+--- a/Src/input.c
++++ b/Src/input.c
+@@ -217,12 +217,34 @@ shinbufrestore(void)
+ static int
+ shingetchar(void)
+ {
+-    int nread;
++    int nread, rsize = isset(SHINSTDIN) ? 1 : SHINBUFSIZE;
+ 
+     if (shinbufptr < shinbufendptr)
+ 	return STOUC(*shinbufptr++);
+ 
+     shinbufreset();
++#ifdef USE_LSEEK
++    if (rsize == 1 && lseek(SHIN, 0, SEEK_CUR) != (off_t)-1)
++	rsize = SHINBUFSIZE;
++    if (rsize > 1) {
++	do {
++	    errno = 0;
++	    nread = read(SHIN, shinbuffer, rsize);
++	} while (nread < 0 && errno == EINTR);
++	if (nread <= 0)
++	    return -1;
++	if (isset(SHINSTDIN) &&
++	    (shinbufendptr = memchr(shinbuffer, '\n', nread))) {
++	    shinbufendptr++;
++	    rsize = (shinbufendptr - shinbuffer);
++	    if (nread > rsize &&
++		lseek(SHIN, -(nread - rsize), SEEK_CUR) < 0)
++		zerr("lseek(%d, %d): %e", SHIN, -(nread - rsize), errno);
++	} else
++	    shinbufendptr = shinbuffer + nread;
++	return STOUC(*shinbufptr++);
++    }
++#endif
+     for (;;) {
+        errno = 0;
+        nread = read(SHIN, shinbufendptr, 1);
+diff --git a/configure.ac b/configure.ac
+index af8c5bba8..42f2837cd 100644
+--- a/configure.ac
++++ b/configure.ac
+@@ -2304,6 +2304,65 @@ if test x$zsh_cv_sys_fifo = xyes; then
+   AC_DEFINE(HAVE_FIFOS)
+ fi
+ 
++dnl -----------
++dnl check that lseek() correctly reports seekability.
++dnl -----------
++AC_CACHE_CHECK(if lseek() correctly reports seekability,
++zsh_cv_sys_lseek,
++[AC_RUN_IFELSE([AC_LANG_SOURCE([[
++#include <stdio.h>
++#include <sys/types.h>
++#include <fcntl.h>
++#include <unistd.h>
++#include <sys/socket.h>
++#include <sys/stat.h>
++int main() {
++    int pipefd[2], fd;
++    off_t ret;
++    char* tmpfile = "seekfiletest.tmp";
++    if ((fd = open(tmpfile, O_CREAT, S_IRUSR)) < 0) {
++	fprintf(stderr, "creating file failed\n");
++	return 1;
++    }
++    ret = lseek(fd, 0, SEEK_CUR);
++    close(fd);
++    unlink(tmpfile);
++    if (ret == (off_t)-1) {
++	fprintf(stderr, "lseek on regular file failed\n");
++	return 1;
++    }
++    if (pipe(pipefd) < 0) {
++	fprintf(stderr, "creating pipe failed\n");
++	return 1;
++    }
++    write(pipefd[1], "abcdefgh", 8);
++    ret = lseek(pipefd[0], 0, SEEK_CUR);
++    close(pipefd[0]);
++    close(pipefd[1]);
++    if (ret != (off_t)-1) {
++	fprintf(stderr, "lseek on pipe succeeded\n");
++	return 1;
++    }
++    if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) {
++	fprintf(stderr, "creating UNIX domain socket failed\n");
++	return 1;
++    }
++    ret = lseek(fd, 0, SEEK_CUR);
++    close(fd);
++    if (ret != (off_t)-1) {
++	fprintf(stderr, "lseek on UNIX domain socket succeeded\n");
++	return 1;
++    }
++    return 0;
++}
++]])],[zsh_cv_sys_lseek=yes],[zsh_cv_sys_lseek=no],[zsh_cv_sys_lseek=yes])
++])
++AH_TEMPLATE([USE_LSEEK],
++[Define to 1 if lseek() can be used for SHIN.])
++if test x$zsh_cv_sys_lseek = xyes; then
++  AC_DEFINE(USE_LSEEK)
++fi
++
+ dnl -----------
+ dnl test for whether link() works
+ dnl for instance, BeOS R4.51 doesn't support hard links yet
+-- 
+2.36.0
+
diff --git a/app-shells/zsh/zsh-5.8.1-r1.ebuild b/app-shells/zsh/zsh-5.8.1-r2.ebuild
index 6cbf8622fe20..dbb80d5ae6d8 100644
--- a/app-shells/zsh/zsh-5.8.1-r1.ebuild
+++ b/app-shells/zsh/zsh-5.8.1-r2.ebuild
@@ -53,6 +53,7 @@ fi
 
 PATCHES=(
 	"${FILESDIR}/${P}-non_interactive_shell_regression_fix.patch"
+	"${FILESDIR}/${P}-performance_regression_fix.patch" #839900
 )
 
 src_prepare() {