From 69fb8c62a31e767be1464a7ccfe2a5bac331c4cc Mon Sep 17 00:00:00 2001
From: Laurent Bercot <ska-skaware@skarnet.org>
Date: Mon, 18 Jul 2022 12:39:01 +0000
Subject:  Fix allread errno management

Signed-off-by: Laurent Bercot <ska@appnovation.com>
---
 doc/libstddjb/allreadwrite.html   | 2 +-
 src/libposixplz/doublefork.c      | 1 +
 src/librandom/random_devurandom.c | 4 ++++
 src/libstddjb/allreadwrite.c      | 7 +------
 src/libstddjb/fd_catn.c           | 4 +++-
 src/libstddjb/openreadfileclose.c | 8 +++++++-
 6 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/doc/libstddjb/allreadwrite.html b/doc/libstddjb/allreadwrite.html
index 1c31022..8003431 100644
--- a/doc/libstddjb/allreadwrite.html
+++ b/doc/libstddjb/allreadwrite.html
@@ -166,7 +166,7 @@ function.
 Equivalent to <code> allreadwrite(&amp;fd_read, fd, s, len) </code>: attempts
 to read <em>len</em> bytes from <em>fd</em> into <em>s</em>, looping around
 <tt>fd_read()</tt> if necessary, until either <em>len</em> bytes are read or
-an error occurs. EOF is reported as EPIPE.
+an error occurs.
 </p>
 
 <p>
diff --git a/src/libposixplz/doublefork.c b/src/libposixplz/doublefork.c
index 6038a9f..c310a9f 100644
--- a/src/libposixplz/doublefork.c
+++ b/src/libposixplz/doublefork.c
@@ -3,6 +3,7 @@
 #include <sys/wait.h>
 #include <unistd.h>
 #include <errno.h>
+
 #include <skalibs/uint64.h>
 #include <skalibs/allreadwrite.h>
 #include <skalibs/djbunix.h>
diff --git a/src/librandom/random_devurandom.c b/src/librandom/random_devurandom.c
index 0ad752b..5f6b791 100644
--- a/src/librandom/random_devurandom.c
+++ b/src/librandom/random_devurandom.c
@@ -1,6 +1,7 @@
 /* ISC license. */
 
 #include <stddef.h>
+#include <errno.h>
 
 #include <skalibs/allreadwrite.h>
 #include <skalibs/strerr2.h>
@@ -11,12 +12,15 @@ void random_devurandom (char *s, size_t n)
 {
   static int random_fd = -1 ;
   size_t r ;
+  int e = errno ;
   if (random_fd < 0)
   {
     random_fd = openbc_read("/dev/urandom") ;
     if (random_fd < 0)
       strerr_diefu2sys(111, "open ", "/dev/urandom") ;
   }
+  errno = EPIPE ;
   r = allread(random_fd, s, n) ;
   if (r < n) strerr_diefu2sys(111, "read from ", "/dev/urandom") ;
+  errno = e ;
 }
diff --git a/src/libstddjb/allreadwrite.c b/src/libstddjb/allreadwrite.c
index 0e9351a..19e4c1c 100644
--- a/src/libstddjb/allreadwrite.c
+++ b/src/libstddjb/allreadwrite.c
@@ -1,6 +1,5 @@
 /* ISC license. */
 
-#include <errno.h>
 #include <skalibs/allreadwrite.h>
 
 size_t allreadwrite (io_func_ref op, int fd, char *buf, size_t len)
@@ -9,11 +8,7 @@ size_t allreadwrite (io_func_ref op, int fd, char *buf, size_t len)
   while (len)
   {
     ssize_t w = (*op)(fd, buf, len) ;
-    if (w <= 0)
-    {
-      if (!w) errno = 0 ;
-      break ;
-    }
+    if (w <= 0) break ;
     written += w ;
     buf += w ;
     len -= w ;
diff --git a/src/libstddjb/fd_catn.c b/src/libstddjb/fd_catn.c
index 182a054..4f1016e 100644
--- a/src/libstddjb/fd_catn.c
+++ b/src/libstddjb/fd_catn.c
@@ -14,10 +14,12 @@ off_t fd_catn (int from, int to, off_t n)
   char buf[BSIZE] ;
   while (n >= BSIZE)
   {
+    size_t v ;
     ssize_t r = fd_read(from, buf, BSIZE) ;
     if (r == -1) return w ;
     if (!r) return (errno = EPIPE, w) ;
-    if (allwrite(to, buf, r) < r) return w ;
+    v = allwrite(to, buf, r) ;
+    if (v < r) return w + v ;
     n -= r ; w += r ;
   }
 
diff --git a/src/libstddjb/openreadfileclose.c b/src/libstddjb/openreadfileclose.c
index afa895a..144f264 100644
--- a/src/libstddjb/openreadfileclose.c
+++ b/src/libstddjb/openreadfileclose.c
@@ -1,6 +1,8 @@
 /* ISC license. */
 
 #include <sys/stat.h>
+#include <errno.h>
+
 #include <skalibs/allreadwrite.h>
 #include <skalibs/stralloc.h>
 #include <skalibs/djbunix.h>
@@ -8,6 +10,7 @@
 int openreadfileclose (char const *file, stralloc *sa, size_t limit)
 {
   size_t n ;
+  int e = errno ;
   int fd = openbc_read(file) ;
   if (fd < 0) return 0 ;
   {
@@ -18,11 +21,14 @@ int openreadfileclose (char const *file, stralloc *sa, size_t limit)
   if (limit && (limit < n)) n = limit ;
   if (!stralloc_ready_tuned(sa, sa->len + n, 0, 0, 1)) goto err ;
   {
-    size_t r = allread(fd, sa->s + sa->len, n) ;
+    size_t r ;
+    errno = EPIPE ;
+    r = allread(fd, sa->s + sa->len, n) ;
     sa->len += r ;
     if (r < n) goto err ;
   }
   fd_close(fd) ;
+  errno = e ;
   return 1 ;
 
 err:
-- 
cgit v1.2.3