Bug #4053: too many of "error 1236: 'binlog truncated in the middle of event' from master"

- Fix my_read/my_write to handle return values from read/write correctly
- Add debugging 'deprecated function' warning to my_lread/my_lwrite
- Add debugging 'error, read/write interrupt not handled' warning to my_quick_read/my_quick_write

There is no test case associated with these changes.  However, this is a conservative change,
and no repeatable test case is available.


mysys/my_lread.c:
  Warn about using deprecated function.
mysys/my_lwrite.c:
  Warn about using deprecated function.
mysys/my_pread.c:
  Handle interrupted read() or write() (EINTR) properly
mysys/my_quick.c:
  Warn about interrupted read() or write(), which is not
  handled by my_quick_read() or my_quick_write().
mysys/my_read.c:
  Handle interrupted read() (EINTR) properly
mysys/my_write.c:
  Handle interrupted write() (EINTR) properly

1 files changed, 6 insertions, 2 deletions

diff --git a/mysys/my_read.c b/mysys/my_read.c
index b7621ac99eb..b59ada20977 100644
--- a/mysys/my_read.c
+++ b/mysys/my_read.c
@@ -51,8 +51,12 @@ uint my_read(File Filedes, byte *Buffer, uint Count, myf MyFlags)
       DBUG_PRINT("warning",("Read only %ld bytes off %ld from %d, errno: %d",
 			    readbytes,Count,Filedes,my_errno));
 #ifdef THREAD
-      if (readbytes == 0 && errno == EINTR)
-	continue;				/* Interrupted */
+      if ((readbytes == 0 || (int) readbytes == -1) && errno == EINTR)
+      {  
+        DBUG_PRINT("debug", ("my_read() was interrupted and returned %d",
+                             (int) readbytes));
+        continue;                              /* Interrupted */
+      }
 #endif
       if (MyFlags & (MY_WME | MY_FAE | MY_FNABP))
       {