lib: Improved istream-file's failing read()/pread() error message.

diff --git a/src/lib/istream-file.c b/src/lib/istream-file.c
index c86fa907e308487dbe7bd24dcecc6122cc2b5b13..888127efc746f7a1f51ba9b99660f53c387be3cd 100644 (file)
--- a/src/lib/istream-file.c
+++ b/src/lib/istream-file.c
@@ -54,6 +54,7 @@ static int i_stream_file_open(struct istream_private *stream)
 static ssize_t i_stream_file_read(struct istream_private *stream)
 {
        struct file_istream *fstream = (struct file_istream *) stream;
+       uoff_t offset;
        size_t size;
        ssize_t ret;
 
@@ -65,11 +66,11 @@ static ssize_t i_stream_file_read(struct istream_private *stream)
                        return -1;
        }
 
+       offset = stream->istream.v_offset + (stream->pos - stream->skip);
        do {
                if (fstream->file) {
                        ret = pread(stream->fd, stream->w_buffer + stream->pos,
-                                   size, stream->istream.v_offset +
-                                   (stream->pos - stream->skip));
+                                   size, offset);
                } else if (fstream->seen_eof) {
                        /* don't try to read() again. EOF from keyboard (^D)
                           requires this to work right. */
@@ -97,6 +98,16 @@ static ssize_t i_stream_file_read(struct istream_private *stream)
                        /* if we get EBADF for a valid fd, it means something's
                           really wrong and we'd better just crash. */
                        i_assert(errno != EBADF);
+                       if (fstream->file) {
+                               io_stream_set_error(&stream->iostream,
+                                       "pread(size=%"PRIuSIZE_T
+                                       " offset=%"PRIuUOFF_T") failed: %m",
+                                       size, offset);
+                       } else {
+                               io_stream_set_error(&stream->iostream,
+                                       "read(size=%"PRIuSIZE_T") failed: %m",
+                                       size);
+                       }
                        stream->istream.stream_errno = errno;
                        return -1;
                }