The file pointer position must be recalculated and set when writev()ing to a

buffered file.
Fix by Davi Arnaut for bug #40963

git-svn-id: http://svn.apache.org/repos/asf/apr/apr/trunk@537066 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 9 insertions, 0 deletions

diff --git a/file_io/unix/readwrite.c b/file_io/unix/readwrite.c
index 3511846d9..412d7c8ba 100644
--- a/file_io/unix/readwrite.c
+++ b/file_io/unix/readwrite.c
@@ -252,6 +252,15 @@ APR_DECLARE(apr_status_t) apr_file_writev(apr_file_t *thefile, const struct iove
         if (rv != APR_SUCCESS) {
             return rv;
         }
+        if (thefile->direction == 0) {
+            /* Position file pointer for writing at the offset we are
+             * logically reading from
+             */
+            apr_int64_t offset = thefile->filePtr - thefile->dataRead + thefile->bufpos;
+            if (offset != thefile->filePtr)
+                lseek(thefile->filedes, offset, SEEK_SET);
+            thefile->bufpos = thefile->dataRead = 0;
+        }
     }
 
 #ifdef HAVE_WRITEV