[client] clipboard: preserve formats after file import failure

Retain non-file clipboard representations while asynchronous file MIME
imports are validated. If an offered URI list is invalid or cannot be
read, publish the retained image and text formats instead of clearing
the clipboard.

client/displayservers/Wayland/clipboard.c

@@ -210,6 +210,17 @@ static bool hasImageMimetype(char ** mimetypes)
   return false;
 }
 
+static size_t getRepresentationTypes(char * const mimetypes[],
+    LG_ClipboardData types[])
+{
+  size_t count = 0;
+  for (enum LG_ClipboardData type = 0;
+      type < LG_CLIPBOARD_DATA_NONE; ++type)
+    if (type != LG_CLIPBOARD_DATA_FILES && mimetypes[type])
+      types[count++] = type;
+  return count;
+}
+
 enum ClipboardInvalidateMode
 {
   CLIPBOARD_INVALIDATE_CONDITIONAL,
@@ -307,6 +318,8 @@ static void fileImportCleanup(void * opaque)
 static void fileImportCallback(uint32_t events, void * opaque)
 {
   struct ClipboardFileImport * import = opaque;
+  LG_ClipboardData             types[LG_CLIPBOARD_DATA_NONE];
+  size_t                       typeCount = 0;
   bool                         complete = false;
   bool                         failed = (events & EPOLLERR) != 0;
   while (!failed)
@@ -337,6 +350,8 @@ static void fileImportCallback(uint32_t events, void * opaque)
   LG_LOCK(wlCb.lock);
   const bool current = wlCb.fileImport == import &&
     wlCb.offer == import->offer;
+  if (current)
+    typeCount = getRepresentationTypes(wlCb.mimetypes, types);
   if (wlCb.fileImport == import)
     wlCb.fileImport = NULL;
   LG_UNLOCK(wlCb.lock);
@@ -345,7 +360,7 @@ static void fileImportCallback(uint32_t events, void * opaque)
         import->data, import->size)))
   {
     clipboardFiles_clearLocal();
-    clipboard_release();
+    clipboard_notifyTypes(types, typeCount);
   }
   if (current)
     waylandPollUnregister(import->fd);
@@ -516,11 +531,9 @@ static void dataDeviceHandleSelection(void * opaque,
     return;
   }
 
-  size_t idx = 0;
   enum LG_ClipboardData types[LG_CLIPBOARD_DATA_NONE];
-  for (enum LG_ClipboardData i = 0; i < LG_CLIPBOARD_DATA_NONE; ++i)
-    if (extra->mimetypes[i])
-      types[idx++] = i;
+  const size_t          typeCount =
+    getRepresentationTypes(extra->mimetypes, types);
 
   char * oldMimetypes[LG_CLIPBOARD_DATA_NONE];
   LG_LOCK(wlCb.lock);
@@ -555,11 +568,11 @@ static void dataDeviceHandleSelection(void * opaque,
     if (!fileImportStart(offer, wlCb.mimetypes[LG_CLIPBOARD_DATA_FILES]))
     {
       clipboardFiles_clearLocal();
-      clipboard_release();
+      clipboard_notifyTypes(types, typeCount);
     }
   }
   else
-    clipboard_notifyTypes(types, idx);
+    clipboard_notifyTypes(types, typeCount);
 }
 
 static void dataDeviceHandleEnter(void * data, struct wl_data_device * device,

client/displayservers/X11/clipboard.c

@@ -84,6 +84,8 @@ struct X11ClipboardFileImport
   size_t           size;
   size_t           capacity;
   bool             incremental;
+  LG_ClipboardData types[LG_CLIPBOARD_DATA_NONE];
+  size_t           typeCount;
 };
 
 struct X11ClipboardState
@@ -858,7 +860,8 @@ static bool fileImportGrowNL(size_t wanted)
   return true;
 }
 
-static bool startFileImport(Atom target)
+static bool startFileImport(Atom target,
+    const LG_ClipboardData types[], size_t typeCount)
 {
   const char * mime = fileMimeForAtom(target);
   if (!mime)
@@ -886,6 +889,8 @@ static bool startFileImport(Atom target)
     .target = target,
     .mime   = mime,
   };
+  memcpy(x11cb.fileImport.types, types, typeCount * sizeof(*types));
+  x11cb.fileImport.typeCount = typeCount;
   XSelectInput(x11.display, window, PropertyChangeMask);
   XConvertSelection(x11.display, x11cb.aCurSelection, target,
       x11atoms.SEL_DATA, window, CurrentTime);
@@ -900,11 +905,18 @@ static void finishFileImport(struct X11ClipboardFileImport import,
   if (!clipboardFiles_setLocal(import.mime, data, size))
   {
     clipboardFiles_clearLocal();
-    clipboard_release();
+    clipboard_notifyTypes(import.types, import.typeCount);
   }
   free(import.data);
 }
 
+static void failFileImport(struct X11ClipboardFileImport import)
+{
+  free(import.data);
+  clipboardFiles_clearLocal();
+  clipboard_notifyTypes(import.types, import.typeCount);
+}
+
 static bool x11CBFileImportSelectionNotify(const XSelectionEvent e)
 {
   Atom type;
@@ -930,8 +942,7 @@ static bool x11CBFileImportSelectionNotify(const XSelectionEvent e)
     LG_UNLOCK(x11cb.lock);
     if (data)
       XFree(data);
-    free(failed.data);
-    clipboard_release();
+    failFileImport(failed);
     return true;
   }
 
@@ -943,8 +954,7 @@ static bool x11CBFileImportSelectionNotify(const XSelectionEvent e)
       LG_UNLOCK(x11cb.lock);
       if (data)
         XFree(data);
-      free(failed.data);
-      clipboard_release();
+      failFileImport(failed);
       return true;
     }
     x11cb.fileImport.incremental = true;
@@ -960,10 +970,7 @@ static bool x11CBFileImportSelectionNotify(const XSelectionEvent e)
   if (valid)
     finishFileImport(import, data, itemCount);
   else
-  {
-    free(import.data);
-    clipboard_release();
-  }
+    failFileImport(import);
   if (data)
     XFree(data);
   return true;
@@ -1000,8 +1007,7 @@ readProperty:
     LG_UNLOCK(x11cb.lock);
     if (data)
       XFree(data);
-    free(failed.data);
-    clipboard_release();
+    failFileImport(failed);
     return;
   }
 
@@ -1026,8 +1032,7 @@ readProperty:
     {
       const struct X11ClipboardFileImport failed = takeFileImportNL();
       LG_UNLOCK(x11cb.lock);
-      free(failed.data);
-      clipboard_release();
+      failFileImport(failed);
       return;
     }
     x11cb.fileImport.propertyOffset += (long)units;
@@ -1412,6 +1417,18 @@ static void x11CBSelectionNotify(const XSelectionEvent e)
 
     // see if we support any of the targets listed
     const Atom * targets = (const Atom *)data;
+    for(int n = 0; n < LG_CLIPBOARD_DATA_NONE; ++n)
+    {
+      if (n == LG_CLIPBOARD_DATA_FILES)
+        continue;
+      for(unsigned long i = 0; i < itemCount; ++i)
+        if (x11cb.aTypes[n] == targets[i])
+        {
+          types[typeCount++] = n;
+          break;
+        }
+    }
+
     Atom fileTarget = None;
     for (unsigned long i = 0; i < itemCount; ++i)
     {
@@ -1438,19 +1455,11 @@ static void x11CBSelectionNotify(const XSelectionEvent e)
     if (fileTarget != None)
     {
       clipboardFiles_clearLocal();
-      if (!startFileImport(fileTarget))
-        clipboard_release();
+      if (!startFileImport(fileTarget, types, typeCount))
+        clipboard_notifyTypes(types, typeCount);
       goto out;
     }
 
-    for(int n = 0; n < LG_CLIPBOARD_DATA_NONE; ++n)
-      for(unsigned long i = 0; i < itemCount; ++i)
-        if (x11cb.aTypes[n] == targets[i])
-        {
-          types[typeCount++] = n;
-          break;
-        }
-
     clipboard_notifyTypes(types, typeCount);
     goto out;
   }