Fix showing share send dialog multiple times by rapidly clicking share icon.

app/src/main/java/com/owncloud/android/ui/helpers/FileOperationsHelper.java

@@ -800,7 +800,9 @@ public class FileOperationsHelper {
         OCCapability capability = fileActivity.getStorageManager().getCapability(fileActivity.getAccount().name);
         SendShareDialog mSendShareDialog = SendShareDialog.newInstance(file, hideNcSharingOptions, capability);
         mSendShareDialog.setFileOperationsHelper(this);
-        mSendShareDialog.show(ft, "TAG_SEND_SHARE_DIALOG");
+        if (fm.findFragmentByTag("TAG_SEND_SHARE_DIALOG") == null) {
+            mSendShareDialog.show(ft, "TAG_SEND_SHARE_DIALOG");
+        }
     }
 
     public void sendFiles(Set<OCFile> files) {