Changeset 85834 in vbox

Timestamp:

Aug 19, 2020 2:05:37 PM (5 years ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

139994

Message:

Shared Clipboard/X11: Return VERR_NO_DATA in X11 callback implementations to make it easier to spot that there is no data available.

Location:

trunk/src/VBox

Files:

• Additions/x11/VBoxClient/clipboard.cpp (modified) (3 diffs)
• HostServices/SharedClipboard/VBoxSharedClipboardSvc-x11.cpp (modified) (2 diffs)

trunk/src/VBox/Additions/x11/VBoxClient/clipboard.cpp

@@ -80 +80 @@
 
 /**
- * Get clipboard data from the host.
+ * Callback implementation for getting clipboard data from the host.
  *
- * @returns VBox result code
+ * @returns VBox status code. VERR_NO_DATA if no data available.
  * @param   pCtx                Our context information.
  * @param   Format              The format of the data being requested.
  * @param   ppv                 On success and if pcb > 0, this will point to a buffer
  *                              to be freed with RTMemFree containing the data read.
- * @param   pcb                 On success, this contains the number of bytes of data
- *                              returned.
+ * @param   pcb                 On success, this contains the number of bytes of data returned.
  */
 DECLCALLBACK(int) ShClX11RequestDataForX11Callback(PSHCLCONTEXT pCtx, SHCLFORMAT Format, void **ppv, uint32_t *pcb)
@@ -138 +137 @@
         }
 
+        if (!cbRead)
+            rc = VERR_NO_DATA;
+
         if (RT_SUCCESS(rc))
         {
@@ -143 +145 @@
             *ppv = pvData;
         }
-
-        /*
-         * Catch other errors. This also catches the case in which the buffer was
-         * too small a second time, possibly because the clipboard contents
-         * changed half-way through the operation.  Since we can't say whether or
-         * not this is actually an error, we just return size 0.
-         */
-        if (RT_FAILURE(rc))
+        else
+        {
+            /*
+             * Catch other errors. This also catches the case in which the buffer was
+             * too small a second time, possibly because the clipboard contents
+             * changed half-way through the operation.  Since we can't say whether or
+             * not this is actually an error, we just return size 0.
+             */
             RTMemFree(pvData);
+        }
     }
 

trunk/src/VBox/HostServices/SharedClipboard/VBoxSharedClipboardSvc-x11.cpp

@@ -316 +316 @@
 
 /**
- * Reads clipboard data from the guest and passes it to the X11 clipboard.
+ * Callback implementation for reading clipboard data from the guest.
  *
  * @note   Runs in Xt event thread.
  *
- * @param  pCtx      Pointer to the host clipboard structure.
- * @param  fFormat   The format in which the data should be transferred
- *                   (VBOX_SHCL_FMT_XXX).
- * @param  ppv       On success and if pcb > 0, this will point to a buffer
- *                   to be freed with RTMemFree containing the data read.
- * @param  pcb       On success, this contains the number of bytes of data
- *                   returned.
+ * @returns VBox status code. VERR_NO_DATA if no data available.
+ * @param   pCtx                Pointer to the host clipboard structure.
+ * @param   fFormat             The format in which the data should be transferred
+ *                              (VBOX_SHCL_FMT_XXX).
+ * @param   ppv                 On success and if pcb > 0, this will point to a buffer
+ *                              to be freed with RTMemFree containing the data read.
+ * @param   pcb                 On success, this contains the number of bytes of data returned.
  */
 DECLCALLBACK(int) ShClX11RequestDataForX11Callback(PSHCLCONTEXT pCtx, SHCLFORMAT fFormat, void **ppv, uint32_t *pcb)
@@ -356 +356 @@
             if (RT_SUCCESS(rc))
             {
-                *ppv = pPayload ? pPayload->pvData : NULL;
-                *pcb = pPayload ? pPayload->cbData : 0;
+                if (   !pPayload
+                    || !pPayload->cbData)
+                {
+                    rc = VERR_NO_DATA;
+                }
+                else
+                {
+                    *ppv = pPayload->pvData;
+                    *pcb = pPayload->cbData;
+                }
             }