libbb: Converted safe_read to safe_write format

Changed safe_read to be symmetrical to safe_write, it shall
never return EINTR because it calls read multiple times,
the error is considered transient.

function                                             old     new   delta
safe_read                                             44      57     +13

Signed-off-by: Martin Lewis <martin.lewis.x84@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 10 insertions, 2 deletions

diff --git a/libbb/read.c b/libbb/read.c
index 5906bc225..a342506a8 100644
--- a/libbb/read.c
+++ b/libbb/read.c
@@ -12,9 +12,17 @@ ssize_t FAST_FUNC safe_read(int fd, void *buf, size_t count)
 {
         ssize_t n;
 
-        do {
+        for (;;) {
                 n = read(fd, buf, count);
-        } while (n < 0 && errno == EINTR);
+                if (n >= 0 || errno != EINTR)
+                        break;
+                /* Some callers set errno=0, are upset when they see EINTR.
+                 * Returning EINTR is wrong since we retry read(),
+                 * the "error" was transient.
+                 */
+                errno = 0;
+                /* repeat the read() */
+        }
 
         return n;
 }