--- a/configure.ac
+++ b/configure.ac
@@ -2203,6 +2203,10 @@
     fi
   fi
 
+  ## Check for Qt functions which have changed their API over time
+  OCTAVE_CHECK_FUNC_FINDFIRST_MODERN
+  OCTAVE_CHECK_FUNC_SETPLACEHOLDERTEXT
+
   case "$canonical_host_type" in
     *-*-mingw* | *-*-msdosmsvc*) win32_terminal=yes ;;
     *)

--- a/libgui/src/m-editor/find-dialog.cc
+++ b/libgui/src/m-editor/find-dialog.cc
@@ -150,8 +150,7 @@
                                       !_backward_check_box->isChecked (),
                                       line,col,
                                       true
-// FIXME: write a proper configure test (is it worth?)
-#if QSCINTILLA_VERSION >= 0x020600
+#ifdef HAVE_FINDFIRST_MODERN
                                       , true
 #endif
                                       );

--- a/libgui/src/qtinfo/webinfo.cc
+++ b/libgui/src/qtinfo/webinfo.cc
@@ -70,8 +70,7 @@
   layout->addLayout (hboxLayout);
 
   _search_line_edit = new QLineEdit(this);
-  // FIXME: maybe put in a better test in configure.ac
-#if QT_VERSION >= 0x040700
+#ifdef HAVE_SETPLACEHOLDERTEXT
   _search_line_edit->setPlaceholderText (tr ("Type here and press \'Return\' to search"));
 #endif
   hboxLayout->addWidget (_search_line_edit);

--- a/m4/acinclude.m4
+++ b/m4/acinclude.m4
@@ -143,6 +143,35 @@
   fi
 ])
 dnl
+dnl Check whether Qscintilla FindFirst function is old (16 inputs) or
+dnl new (17 inputs).
+dnl FIXME: This test uses a version number.  It potentially could
+dnl        be re-written to actually call the function, but is it worth it?
+dnl
+AC_DEFUN([OCTAVE_CHECK_FUNC_FINDFIRST_MODERN], [
+  AC_CACHE_CHECK([whether Qscintilla FindFirst uses 16 or 17 input arguments],
+    [octave_cv_func_findfirst_modern],
+    [AC_LANG_PUSH(C++)
+    save_CPPFLAGS="$CPPFLAGS"
+    CPPFLAGS="-I$QT_INCDIR -I$QT_INCDIR/Qt $CPPFLAGS"
+    AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+        #include <Qsci/qsciglobal.h>
+        ]], [[
+        #if QSCINTILLA_VERSION < 0x020600
+          Old Form Found;
+        #endif
+        ]])],
+      octave_cv_func_findfirst_modern=yes,
+      octave_cv_func_findfirst_modern=no)
+    CPPFLAGS="$save_CPPFLAGS"
+    AC_LANG_POP(C++)
+  ])
+  if test $octave_cv_func_findfirst_modern = "yes"; then
+    AC_DEFINE(HAVE_FINDFIRST_MODERN, 1, 
+      [Define to 1 if Qscintilla FindFirst uses modern form with 17 inputs.])
+  fi
+])
+dnl
 dnl Check if Fortran compiler has the intrinsic function ISNAN.
 dnl
 AC_DEFUN([OCTAVE_CHECK_FUNC_FORTRAN_ISNAN], [
@@ -193,6 +222,34 @@
   fi
 ])
 dnl
+dnl Check whether Qscintilla SetPlaceholderText function exists.
+dnl FIXME: This test uses a version number.  It potentially could
+dnl        be re-written to actually call the function, but is it worth it?
+dnl
+AC_DEFUN([OCTAVE_CHECK_FUNC_SETPLACEHOLDERTEXT], [
+  AC_CACHE_CHECK([whether Qt has SetPlaceholderText function],
+    [octave_cv_func_setplaceholdertext],
+    [AC_LANG_PUSH(C++)
+    save_CPPFLAGS="$CPPFLAGS"
+    CPPFLAGS="-I$QT_INCDIR $CPPFLAGS"
+    AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+        #include <Qt/qglobal.h>
+        ]], [[
+        #if QT_VERSION < 0x040700
+          No SetPlacholderText function available;
+        #endif
+        ]])],
+      octave_cv_func_setplaceholdertext=yes,
+      octave_cv_func_setplaceholdertext=no)
+    CPPFLAGS="$save_CPPFLAGS"
+    AC_LANG_POP(C++)
+  ])
+  if test $octave_cv_func_setplaceholdertext = "yes"; then
+    AC_DEFINE(HAVE_SETPLACEHOLDERTEXT, 1, 
+      [Define to 1 if you have the Qt SetPlaceholderText function.])
+  fi
+])
+dnl
 dnl Check whether HDF5 library has version 1.6 API functions.
 dnl
 AC_DEFUN([OCTAVE_CHECK_HDF5_HAS_VER_16_API], [