cmake-gui: do not set search filter if regex is invalid

Fixes: #24248

Source/QtDialog/CMakeSetupDialog.cxx

@@ -1344,7 +1344,8 @@ void CMakeSetupDialog::showUserChanges()
 void CMakeSetupDialog::setSearchFilter(const QString& str)
 {
   this->CacheValues->selectionModel()->clear();
-  this->CacheValues->setSearchFilter(str);
+  const bool valid = this->CacheValues->setSearchFilter(str);
+  QtCMake::setSearchFilterColor(this->Search, valid);
 }
 
 void CMakeSetupDialog::doOutputContextMenu(QPoint pt)

Source/QtDialog/EnvironmentDialog.cxx

@@ -2,6 +2,7 @@
    file Copyright.txt or https://cmake.org/licensing for details.  */
 #include "EnvironmentDialog.h"
 
+#include "QCMakeWidgets.h"
 #include <QDialogButtonBox>
 #include <QGridLayout>
 #include <QItemSelectionModel>
@@ -110,14 +111,11 @@ EnvironmentDialog::EnvironmentDialog(const QProcessEnvironment& environment,
                    &EnvironmentDialog::addEntry);
   QObject::connect(this->RemoveEntry, &QAbstractButton::clicked, this,
                    &EnvironmentDialog::removeSelectedEntries);
-#if (QT_VERSION >= QT_VERSION_CHECK(5, 15, 0))
-  QObject::connect(this->Search, &QLineEdit::textChanged, this->m_filter,
-                   QOverload<const QString&>::of(
-                     &EnvironmentSearchFilter::setFilterRegularExpression));
-#else
-  QObject::connect(this->Search, &QLineEdit::textChanged, this->m_filter,
-                   &EnvironmentSearchFilter::setFilterFixedString);
-#endif
+  QObject::connect(
+    this->Search, &QLineEdit::textChanged, [this](const QString& text) {
+      const bool valid = QtCMake::setSearchFilter(this->m_filter, text);
+      QtCMake::setSearchFilterColor(this->Search, valid);
+    });
   QObject::connect(this->Environment->selectionModel(),
                    &QItemSelectionModel::selectionChanged, this,
                    &EnvironmentDialog::selectionChanged);

Source/QtDialog/QCMakeCacheView.cxx

@@ -167,13 +167,9 @@ bool QCMakeCacheView::showAdvanced() const
   return this->AdvancedFilter->showAdvanced();
 }
 
-void QCMakeCacheView::setSearchFilter(const QString& s)
+bool QCMakeCacheView::setSearchFilter(const QString& s)
 {
-#if (QT_VERSION >= QT_VERSION_CHECK(5, 15, 0))
-  this->SearchFilter->setFilterRegularExpression(s);
-#else
-  this->SearchFilter->setFilterFixedString(s);
-#endif
+  return QtCMake::setSearchFilter(this->SearchFilter, s);
 }
 
 QCMakeCacheModel::QCMakeCacheModel(QObject* p)

Source/QtDialog/QCMakeCacheView.h

@@ -28,12 +28,13 @@ public:
 
   QSize sizeHint() const { return QSize(200, 200); }
 
+  // set the search filter string.  any property key or value not matching will
+  // be filtered out
+  bool setSearchFilter(const QString&);
+
 public slots:
   // set whether to show advanced entries
   void setShowAdvanced(bool);
-  // set the search filter string.  any property key or value not matching will
-  // be filtered out
-  void setSearchFilter(const QString&);
 
 protected:
   QModelIndex moveCursor(CursorAction, Qt::KeyboardModifiers);

Source/QtDialog/QCMakeWidgets.cxx

@@ -10,8 +10,13 @@
 #include <QFileDialog>
 #include <QFileInfo>
 #include <QResizeEvent>
+#include <QSortFilterProxyModel>
 #include <QToolButton>
 
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 15, 0))
+#  include <QRegularExpression>
+#endif
+
 #if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
 #  include <QFileSystemModel>
 #else
@@ -155,3 +160,32 @@ QString QCMakeFileCompleter::pathFromIndex(const QModelIndex& idx) const
 {
   return QDir::fromNativeSeparators(QCompleter::pathFromIndex(idx));
 }
+
+namespace QtCMake {
+bool setSearchFilter(QSortFilterProxyModel* model, const QString& searchString)
+{
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 15, 0))
+  QRegularExpression const regex(searchString,
+                                 QRegularExpression::CaseInsensitiveOption |
+                                   QRegularExpression::DontCaptureOption);
+  if (regex.isValid()) {
+    model->setFilterRegularExpression(regex);
+    return true;
+  }
+  model->setFilterFixedString(QString{});
+  return false;
+#else
+  model->setFilterFixedString(searchString);
+  return true;
+#endif
+}
+
+void setSearchFilterColor(QLineEdit* edit, bool valid)
+{
+  QPalette palette;
+  if (!valid) {
+    palette.setColor(QPalette::Base, Qt::red);
+  }
+  edit->setPalette(palette);
+}
+}

Source/QtDialog/QCMakeWidgets.h

@@ -9,6 +9,7 @@
 #include <QLineEdit>
 
 class QToolButton;
+class QSortFilterProxyModel;
 
 // common widgets for Qt based CMake
 
@@ -76,3 +77,10 @@ public:
     }
   }
 };
+
+namespace QtCMake {
+bool setSearchFilter(QSortFilterProxyModel* model,
+                     const QString& searchString);
+
+void setSearchFilterColor(QLineEdit* edit, bool valid);
+}