[backport] Make sure [fcopy -size ... -command ...] always calls the callback asynchronously, even for size zero.

3 files changed, 82 insertions, 2 deletions

diff --git a/ChangeLog b/ChangeLog
index 76cb2fb..87226e4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2010-12-10 Alexandre Ferrieux  <ferrieux@users.sourceforge.net>
+
+	* generic/tclIO.c: [backport] Make sure [fcopy -size ... -command ...] always
+	* tests/io.test:   calls the callback asynchronously, even for size zero.
+
 2010-12-03  Jeff Hobbs  <jeffh@ActiveState.com>
 
 	* generic/tclUtil.c (TclReToGlob): add extra check for multiple
diff --git a/generic/tclIO.c b/generic/tclIO.c
index ebbb3d1..1bd4cdd 100644
--- a/generic/tclIO.c
+++ b/generic/tclIO.c
@@ -10,7 +10,7 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclIO.c,v 1.137.2.17 2010/03/20 17:53:07 dkf Exp $
+ * RCS: @(#) $Id: tclIO.c,v 1.137.2.18 2010/12/10 17:16:08 ferrieux Exp $
  */
 
 #include "tclInt.h"
@@ -8467,6 +8467,33 @@ Tcl_FileEventObjCmd(
 /*
  *----------------------------------------------------------------------
  *
+ * ZeroTransferTimerProc --
+ *
+ *	Timer handler scheduled by TclCopyChannel so that -command is
+ *	called asynchronously even when -size is 0.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Calls CopyData for -command invocation.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+ZeroTransferTimerProc(
+    ClientData clientData)
+{
+    /* calling CopyData with mask==0 still implies immediate invocation of the
+     *  -command callback, and completion of the fcopy.
+     */
+    CopyData(clientData, 0);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
  * TclCopyChannel --
  *
  *	This routine copies data from one channel to another, either
@@ -8573,6 +8600,16 @@ TclCopyChannel(
     outStatePtr->csPtrW = csPtr;
 
     /*
+     * Special handling of -size 0 async transfers, so that the -command is
+     * still called asynchronously.
+     */
+
+    if ((nonBlocking == CHANNEL_NONBLOCKING) && (toRead == 0)) {
+        Tcl_CreateTimerHandler(0, ZeroTransferTimerProc, csPtr);
+        return 0;
+    }
+
+    /*
      * Start copying data between the channels.
      */
 
diff --git a/tests/io.test b/tests/io.test
index 06e0ecc..5449a0d 100644
--- a/tests/io.test
+++ b/tests/io.test
@@ -13,7 +13,7 @@
 # See the file "license.terms" for information on usage and redistribution
 # of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 #
-# RCS: @(#) $Id: io.test,v 1.80.2.14 2009/11/12 15:47:20 dgp Exp $
+# RCS: @(#) $Id: io.test,v 1.80.2.15 2010/12/10 17:16:08 ferrieux Exp $
 
 if {[catch {package require tcltest 2}]} {
     puts stderr "Skipping tests in [info script].  tcltest 2 required."
@@ -7007,6 +7007,44 @@ test io-53.8a {CopyData: async callback and error handling, Bug 1932639, at eof}
     removeFile foo
     removeFile bar
 } -result {1 sync/OK {CMD 0}}
+test io-53.8b {CopyData: async callback and -size 0} -setup {
+    # copy progress callback. errors out intentionally
+    proc ::cmd args {
+	lappend ::RES "CMD $args"
+	set ::forever has-been-reached
+	return
+    }
+    # Files we use for our channels
+    set foo [makeFile ashgdfashdgfasdhgfasdhgf foo]
+    set bar [makeFile {} bar]
+    # Channels to copy between
+    set f [open $foo r] ; fconfigure $f -translation binary
+    set g [open $bar w] ; fconfigure $g -translation binary -buffering none
+} -constraints {stdio openpipe fcopy} -body {
+	set ::RES {}
+    # Run the copy. Should not invoke -command now.
+    fcopy $f $g -size 0 -command ::cmd
+    # Check that -command was not called synchronously
+    lappend ::RES [expr {([llength $::RES] > 1) ? "sync/FAIL" : "sync/OK"}]
+    # Now let the async part happen. Should capture the eof in cmd
+    # If not break the event loop via timer.
+    set token [after 1000 {
+	lappend ::RES {cmd/FAIL timeout}
+	set ::forever has-been-reached
+    }]
+    vwait ::forever
+    catch {after cancel $token}
+    # Report
+    set ::RES
+} -cleanup {
+    close $f
+    close $g
+    catch {unset ::RES}
+    catch {unset ::forever}
+    rename ::cmd {}
+    removeFile foo
+    removeFile bar
+} -result {sync/OK {CMD 0}}
 test io-53.9 {CopyData: -size and event interaction, Bug 780533} -setup {
     set out [makeFile {} out]
     set err [makeFile {} err]