fix image title constraint

src/utils/vutils.cpp

@@ -47,7 +47,7 @@ const QString VUtils::c_imageLinkRegExp = QString("\\!\\[([^\\]]*)\\]\\(\\s*([^\
                                                   "(=(\\d*)x(\\d*))?\\s*"
                                                   "\\)");
 
-const QString VUtils::c_imageTitleRegExp = QString("[\\w\\(\\)@#%\\*\\-\\+=\\?<>\\,\\.\\s]*");
+const QString VUtils::c_imageTitleRegExp = QString("[^\\[\\]]*");
 
 const QString VUtils::c_linkRegExp = QString("\\[([^\\]]*)\\]\\(\\s*([^\\)\"'\\s]+)\\s*"
                                              "((\"[^\"\\)\\n]*\")|('[^'\\)\\n]*'))?\\s*"

src/vtextblockdata.cpp

@@ -38,9 +38,7 @@ bool VTextBlockData::insertPreviewInfo(VPreviewInfo *p_info)
             tsUpdated = true;
             break;
         } else if (p_info->m_imageInfo.intersect(ele->m_imageInfo)) {
-            // The new one intersect with an old one.
-            // Remove the old one.
-            Q_ASSERT(ele->m_timeStamp < p_info->m_timeStamp);
+            // Two preview intersect.
             delete ele;
             it = m_previews.erase(it);
         } else {