diff --git a/.github/workflows/make-alpine.yaml b/.github/workflows/make-alpine.yaml
index 3b78a4104f..0a4cb6b089 100644
--- a/.github/workflows/make-alpine.yaml
+++ b/.github/workflows/make-alpine.yaml
@@ -168,7 +168,12 @@ jobs:
           echo gfortran --version
           gfortran --version
           mkdir .build
+          echo "::group::Run configure script"
           cd .build && ../configure
+          echo "::endgroup::"
+          echo "::group::Show config.log"
+          cat ./config.log
+          echo "::endgroup::"
 
       - name: build
         # Parallel make seems to fail intermittently when creating the figures
diff --git a/.github/workflows/make-macos.yaml b/.github/workflows/make-macos.yaml
index b9ca1b2476..50e869bb66 100644
--- a/.github/workflows/make-macos.yaml
+++ b/.github/workflows/make-macos.yaml
@@ -68,7 +68,7 @@ jobs:
           brew install --overwrite python@3.12 python@3.13
           brew reinstall gcc
           brew install arpack epstool fftw fig2dev fltk fontconfig freetype \
-            ghostscript gl2ps glpk gnuplot graphicsmagick hdf5 libsndfile \
+            ghostscript gl2ps glpk gnuplot graphicsmagick hdf5 libiconv libsndfile \
             libtool openblas pcre2 portaudio pstoedit qhull qrupdate \
             qscintilla2 qt@${{ matrix.qt }} rapidjson readline suite-sparse sundials texinfo \
             ccache gnu-sed openjdk pkg-config \
@@ -81,6 +81,7 @@ jobs:
           echo "${HOMEBREW_PREFIX}/opt/texinfo/bin" >> $GITHUB_PATH
           echo "${HOMEBREW_PREFIX}/opt/bison/bin" >> $GITHUB_PATH
           echo "${HOMEBREW_PREFIX}/opt/gnu-sed/libexec/gnubin" >> $GITHUB_PATH
+          echo "${HOMEBREW_PREFIX}/opt/libiconv/bin" >> $GITHUB_PATH
 
       - name: prepare ccache
         # create key with human readable timestamp
@@ -138,12 +139,13 @@ jobs:
           echo gfortran --version
           gfortran --version
           mkdir .build
+          echo "::group::Run configure script"
           cd .build && ../configure \
             CXX="${CXX} ${{ matrix.cxx-compiler-flags }}" \
             F77="ccache gfortran" \
-            CPPFLAGS="-I${HOMEBREW_PREFIX}/opt/gettext/include -I${HOMEBREW_PREFIX}/opt/icu4c/include -I${HOMEBREW_PREFIX}/opt/qt@${{ matrix.qt }}/include -I${HOMEBREW_PREFIX}/opt/readline/include -I${HOMEBREW_PREFIX}/opt/sqlite/include $MY_CPPFLAGS -I${HOMEBREW_PREFIX}/include" \
+            CPPFLAGS="-I${HOMEBREW_PREFIX}/opt/gettext/include -I${HOMEBREW_PREFIX}/opt/icu4c/include -I${HOMEBREW_PREFIX}/opt/libiconv/include -I${HOMEBREW_PREFIX}/opt/qt@${{ matrix.qt }}/include -I${HOMEBREW_PREFIX}/opt/readline/include -I${HOMEBREW_PREFIX}/opt/sqlite/include $MY_CPPFLAGS -I${HOMEBREW_PREFIX}/include" \
             CXXFLAGS="-O2 -g" \
-            LDFLAGS="-L${HOMEBREW_PREFIX}/opt/bison/lib -L${HOMEBREW_PREFIX}/opt/gettext/lib -L${HOMEBREW_PREFIX}/opt/icu4c/lib -L${HOMEBREW_PREFIX}/opt/readline/lib -L${HOMEBREW_PREFIX}/opt/sqlite/lib $MY_LDFLAGS -L${HOMEBREW_PREFIX}/lib" \
+            LDFLAGS="-L${HOMEBREW_PREFIX}/opt/bison/lib -L${HOMEBREW_PREFIX}/opt/gettext/lib -L${HOMEBREW_PREFIX}/opt/icu4c/lib -L${HOMEBREW_PREFIX}/opt/libiconv/lib -L${HOMEBREW_PREFIX}/opt/readline/lib -L${HOMEBREW_PREFIX}/opt/sqlite/lib $MY_LDFLAGS -L${HOMEBREW_PREFIX}/lib" \
             PKG_CONFIG_PATH="${HOMEBREW_PREFIX}/opt/openblas/lib/pkgconfig:${HOMEBREW_PREFIX}/opt/icu4c/lib/pkgconfig:${HOMEBREW_PREFIX}/${{ matrix.qt-pkg-config-path }}" \
             --with-qt=${{ matrix.qt }} \
             QCOLLECTIONGENERATOR="qhelpgenerator" \
@@ -151,6 +153,10 @@ jobs:
             --with-blas="-L${HOMEBREW_PREFIX}/opt/openblas/lib -lopenblas" \
             --with-java-homedir="${HOMEBREW_PREFIX}/opt/openjdk" \
             --prefix="${HOME}/usr"
+          echo "::endgroup::"
+          echo "::group::Show config.log"
+          cat ./config.log
+          echo "::endgroup::"
 
       - name: build
         run: make -C ./.build all -j3 V=1
diff --git a/.github/workflows/make-mingw.yaml b/.github/workflows/make-mingw.yaml
index ff4a2767f1..9f274d3e91 100644
--- a/.github/workflows/make-mingw.yaml
+++ b/.github/workflows/make-mingw.yaml
@@ -177,11 +177,16 @@ jobs:
           echo $F77 --version
           $F77 --version
           mkdir .build
+          echo "::group::Run configure script"
           cd .build && ../configure \
             JAVA_HOME="" \
             --enable-relocate-all \
             --disable-docs \
             ${{ matrix.extra-config-flags }}
+          echo "::endgroup::"
+          echo "::group::Show config.log"
+          cat ./config.log
+          echo "::endgroup::"
 
       - name: build
         # Spawning processes seems to have a big overhead on this platform. Use a somewhat larger number of parallel processes to compensate for that.
diff --git a/.github/workflows/make-ubuntu.yaml b/.github/workflows/make-ubuntu.yaml
index b935e31f7c..143cf5bbb6 100644
--- a/.github/workflows/make-ubuntu.yaml
+++ b/.github/workflows/make-ubuntu.yaml
@@ -109,10 +109,15 @@ jobs:
           echo gfortran --version
           gfortran --version
           mkdir .build
+          echo "::group::Run configure script"
           cd .build && ../configure \
             CPPFLAGS="-I/usr/include/hdf5/serial -I/usr/include/suitesparse" \
             LDFLAGS="-L/usr/lib/$(dpkg-architecture -qDEB_HOST_MULTIARCH)/hdf5/serial" \
             ${{ matrix.extra-config-flags }}
+          echo "::endgroup::"
+          echo "::group::Show config.log"
+          cat ./config.log
+          echo "::endgroup::"
 
       - name: build
         # Parallel make seems to fail intermittently when creating the figures
diff --git a/bootstrap b/bootstrap
index 4beae0e912..6acad165a3 100755
--- a/bootstrap
+++ b/bootstrap
@@ -1,7 +1,7 @@
 #! /bin/sh
 # Bootstrap this package from checked-out sources.
 
-scriptversion=2024-04-13.15; # UTC
+scriptversion=2024-07-04.10; # UTC
 
 # Copyright (C) 2003-2024 Free Software Foundation, Inc.
 #
@@ -117,7 +117,8 @@ Gnulib sources can be fetched in various ways:
 
  * Otherwise, if the 'gnulib' directory does not exist, Gnulib sources
    are cloned into that directory using git from \$GNULIB_URL, defaulting
-   to $default_gnulib_url.
+   to $default_gnulib_url; if GNULIB_REFDIR is set and is a git repository
+   its contents may be used to accelerate the process.
    If the configuration variable GNULIB_REVISION is set in bootstrap.conf,
    then that revision is checked out.
 
@@ -237,7 +238,7 @@ fi
 # ----------------------------------------------------------------------------
 
 # Local Variables:
-# eval: (add-hook 'before-save-hook 'time-stamp)
+# eval: (add-hook 'before-save-hook 'time-stamp nil t)
 # time-stamp-start: "scriptversion="
 # time-stamp-format: "%:y-%02m-%02d.%02H"
 # time-stamp-time-zone: "UTC0"
diff --git a/bootstrap-funclib.sh b/bootstrap-funclib.sh
index f7905eb208..7c125533e0 100644
--- a/bootstrap-funclib.sh
+++ b/bootstrap-funclib.sh
@@ -1,6 +1,6 @@
 # A library of shell functions for autopull.sh, autogen.sh, and bootstrap.
 
-scriptlibversion=2024-04-28.09; # UTC
+scriptlibversion=2024-11-12.21; # UTC
 
 # Copyright (C) 2003-2024 Free Software Foundation, Inc.
 #
@@ -468,11 +468,10 @@ prepare_GNULIB_SRCDIR ()
       # if the GNULIB_REVISION is a commit hash that only exists in
       # origin. In this case, we need a 'git fetch' and then retry
       # 'git checkout "$GNULIB_REVISION"'.
-      (cd "$GNULIB_SRCDIR" \
-       && { git checkout "$GNULIB_REVISION" 2>/dev/null \
-            || { git fetch origin && git checkout "$GNULIB_REVISION"; }
-          }
-      ) || exit $?
+      git -C "$GNULIB_SRCDIR" checkout "$GNULIB_REVISION" 2>/dev/null \
+      || { git -C "$GNULIB_SRCDIR" fetch origin \
+           && git -C "$GNULIB_SRCDIR" checkout "$GNULIB_REVISION"; } \
+      || exit $?
     fi
   else
     if ! $use_git; then
@@ -491,7 +490,7 @@ prepare_GNULIB_SRCDIR ()
       if test -n "$GNULIB_REFDIR" && test -d "$GNULIB_REFDIR"/.git; then
         # Use GNULIB_REFDIR as a reference.
         echo "$0: getting gnulib files..."
-        git submodule update --init --reference "$GNULIB_REFDIR" "$gnulib_path" \
+        git submodule update --init --reference "$GNULIB_REFDIR" "$gnulib_path"\
           || exit $?
       else
         # GNULIB_REFDIR is not set or not usable. Ignore it.
@@ -509,33 +508,65 @@ prepare_GNULIB_SRCDIR ()
         # The subdirectory 'gnulib' does not yet exist. Clone into it.
         echo "$0: getting gnulib files..."
         trap cleanup_gnulib HUP INT PIPE TERM
-        shallow=
-        if test -z "$GNULIB_REVISION"; then
-          if git clone -h 2>&1 | grep -- --depth > /dev/null; then
-            shallow='--depth 2'
-          fi
-          git clone $shallow ${GNULIB_URL:-$default_gnulib_url} "$gnulib_path" \
-            || cleanup_gnulib
+        gnulib_url=${GNULIB_URL:-$default_gnulib_url}
+        if test -n "$GNULIB_REFDIR" && test -d "$GNULIB_REFDIR"/.git; then
+          # Use GNULIB_REFDIR as a reference.
+          git clone "$GNULIB_REFDIR" "$gnulib_path" \
+          && git -C "$gnulib_path" remote set-url origin "$gnulib_url" \
+          && if test -z "$GNULIB_REVISION"; then
+               git -C "$gnulib_path" pull origin \
+               && {
+                 # We want the default branch of "$gnulib_url" (since that's
+                 # the behaviour if GNULIB_REFDIR is not specified), not the
+                 # current branch of "$GNULIB_REFDIR".
+                 default_branch=`LC_ALL=C git -C "$gnulib_path" \
+                                              remote show origin \
+                                 | sed -n -e 's/^ *HEAD branch: //p'`
+                 test -n "$default_branch" || default_branch='master'
+                 git -C "$gnulib_path" checkout "$default_branch"
+               }
+             else
+               # The 'git checkout "$GNULIB_REVISION"' command succeeds if the
+               # GNULIB_REVISION is a commit hash that exists locally, or if it
+               # is a branch name that can be fetched from origin. It fails,
+               # however, if the GNULIB_REVISION is a commit hash that only
+               # exists in origin. In this case, we need a 'git fetch' and then
+               # retry 'git checkout "$GNULIB_REVISION"'.
+               git -C "$gnulib_path" checkout "$GNULIB_REVISION" 2>/dev/null \
+               || { git -C "$gnulib_path" fetch origin \
+                    && git -C "$gnulib_path" checkout "$GNULIB_REVISION"; }
+             fi \
+          || cleanup_gnulib
         else
-          if git fetch -h 2>&1 | grep -- --depth > /dev/null; then
-            shallow='--depth 2'
+          # GNULIB_REFDIR is not set or not usable. Ignore it.
+          shallow=
+          if test -z "$GNULIB_REVISION"; then
+            if git clone -h 2>&1 | grep -- --depth > /dev/null; then
+              shallow='--depth 2'
+            fi
+            git clone $shallow "$gnulib_url" "$gnulib_path" \
+              || cleanup_gnulib
+          else
+            if git fetch -h 2>&1 | grep -- --depth > /dev/null; then
+              shallow='--depth 2'
+            fi
+            mkdir -p "$gnulib_path"
+            # Only want a shallow checkout of $GNULIB_REVISION, but git does not
+            # support cloning by commit hash. So attempt a shallow fetch by
+            # commit hash to minimize the amount of data downloaded and changes
+            # needed to be processed, which can drastically reduce download and
+            # processing time for checkout. If the fetch by commit fails, a
+            # shallow fetch can not be performed because we do not know what the
+            # depth of the commit is without fetching all commits. So fall back
+            # to fetching all commits.
+            git -C "$gnulib_path" init
+            git -C "$gnulib_path" remote add origin "$gnulib_url"
+            git -C "$gnulib_path" fetch $shallow origin "$GNULIB_REVISION" \
+              || git -C "$gnulib_path" fetch origin \
+              || cleanup_gnulib
+            git -C "$gnulib_path" reset --hard FETCH_HEAD
+            git -C "$gnulib_path" checkout "$GNULIB_REVISION" || cleanup_gnulib
           fi
-          mkdir -p "$gnulib_path"
-          # Only want a shallow checkout of $GNULIB_REVISION, but git does not
-          # support cloning by commit hash. So attempt a shallow fetch by commit
-          # hash to minimize the amount of data downloaded and changes needed to
-          # be processed, which can drastically reduce download and processing
-          # time for checkout. If the fetch by commit fails, a shallow fetch can
-          # not be performed because we do not know what the depth of the commit
-          # is without fetching all commits. So fall back to fetching all
-          # commits.
-          git -C "$gnulib_path" init
-          git -C "$gnulib_path" remote add origin ${GNULIB_URL:-$default_gnulib_url}
-          git -C "$gnulib_path" fetch $shallow origin "$GNULIB_REVISION" \
-            || git -C "$gnulib_path" fetch origin \
-            || cleanup_gnulib
-          git -C "$gnulib_path" reset --hard FETCH_HEAD
-          (cd "$gnulib_path" && git checkout "$GNULIB_REVISION") || cleanup_gnulib
         fi
         trap - HUP INT PIPE TERM
       else
@@ -543,16 +574,15 @@ prepare_GNULIB_SRCDIR ()
         if test -n "$GNULIB_REVISION"; then
           if test -d "$gnulib_path/.git"; then
             # The 'git checkout "$GNULIB_REVISION"' command succeeds if the
-            # GNULIB_REVISION is a commit hash that exists locally, or if it is
-            # branch name that can be fetched from origin. It fails, however,
-            # if the GNULIB_REVISION is a commit hash that only exists in
-            # origin. In this case, we need a 'git fetch' and then retry
-            # 'git checkout "$GNULIB_REVISION"'.
-            (cd "$gnulib_path" \
-             && { git checkout "$GNULIB_REVISION" 2>/dev/null \
-                  || { git fetch origin && git checkout "$GNULIB_REVISION"; }
-                }
-            ) || exit $?
+            # GNULIB_REVISION is a commit hash that exists locally, or if it
+            # is a branch name that can be fetched from origin. It fails,
+            # however, if the GNULIB_REVISION is a commit hash that only
+            # exists in origin. In this case, we need a 'git fetch' and then
+            # retry 'git checkout "$GNULIB_REVISION"'.
+            git -C "$gnulib_path" checkout "$GNULIB_REVISION" 2>/dev/null \
+            || { git -C "$gnulib_path" fetch origin \
+                 && git -C "$gnulib_path" checkout "$GNULIB_REVISION"; } \
+            || exit $?
           else
             die "Error: GNULIB_REVISION is specified in bootstrap.conf," \
                 "but '$gnulib_path' contains no git history"
@@ -682,7 +712,8 @@ Gnulib sources can be fetched in various ways:
 
  * Otherwise, if the 'gnulib' directory does not exist, Gnulib sources
    are cloned into that directory using git from \$GNULIB_URL, defaulting
-   to $default_gnulib_url.
+   to $default_gnulib_url; if GNULIB_REFDIR is set and is a git repository
+   its contents may be used to accelerate the process.
    If the configuration variable GNULIB_REVISION is set in bootstrap.conf,
    then that revision is checked out.
 
@@ -850,9 +881,7 @@ update_po_files() {
     && ls "$ref_po_dir"/*.po 2>/dev/null |
       sed 's|.*/||; s|\.po$||' > "$po_dir/LINGUAS" || return
 
-  langs=$(cd $ref_po_dir && echo *.po | sed 's/\.po//g')
-  test "$langs" = '*' && langs=x
-  for po in $langs; do
+  for po in x $(ls $ref_po_dir | sed -n 's/\.po$//p'); do
     case $po in x) continue;; esac
     new_po="$ref_po_dir/$po.po"
     cksum_file="$ref_po_dir/$po.s1"
@@ -1216,6 +1245,20 @@ autogen()
     $gnulib_tool $gnulib_tool_options --import $gnulib_modules \
       || die "gnulib-tool failed"
 
+    if test $with_gettext = yes && test ! -f $m4_base/gettext.m4; then
+      # The gnulib-tool invocation has removed $m4_base/gettext.m4, that the
+      # AUTOPOINT invocation had installed. This can occur when the gnulib
+      # module 'gettext' was previously present but is now not present any more.
+      # Repeat the AUTOPOINT invocation and the gnulib-tool invocation.
+
+      echo "$0: $AUTOPOINT --force"
+      $AUTOPOINT --force || return
+
+      echo "$0: $gnulib_tool $gnulib_tool_options --import ..."
+      $gnulib_tool $gnulib_tool_options --import $gnulib_modules \
+        || die "gnulib-tool failed"
+    fi
+
     for file in $gnulib_files; do
       symlink_to_dir "$GNULIB_SRCDIR" $file \
         || die "failed to symlink $file"
@@ -1301,7 +1344,7 @@ autogen()
       || die 'cannot generate runtime-po/Makevars'
 
       # Copy identical files from po to runtime-po.
-      (cd po && cp -p Makefile.in.in *-quot *.header *.sed *.sin ../runtime-po)
+      cp -p po/Makefile.in.in po/*-quot po/*.header po/*.sed po/*.sin runtime-po
     fi
   fi
 
@@ -1313,7 +1356,7 @@ autogen()
 # ----------------------------------------------------------------------------
 
 # Local Variables:
-# eval: (add-hook 'before-save-hook 'time-stamp)
+# eval: (add-hook 'before-save-hook 'time-stamp nil t)
 # time-stamp-start: "scriptlibversion="
 # time-stamp-format: "%:y-%02m-%02d.%02H"
 # time-stamp-time-zone: "UTC0"
diff --git a/bootstrap.conf b/bootstrap.conf
index 13a54ee7f1..19e3d83aa6 100644
--- a/bootstrap.conf
+++ b/bootstrap.conf
@@ -49,8 +49,8 @@ gnulib_modules="
   fpucw
   frexp
   frexpf
-  fseek
-  ftell
+  fseeko
+  ftello
   ftruncate
   getcwd
   gethostname
@@ -204,7 +204,7 @@ source_base="libgnu"
 #
 # See also: https://lists.gnu.org/archive/html/bug-gnulib/2020-08/msg00150.html
 
-: ${GNULIB_REVISION=6213c5bd72d15ca5e1ea9c34122899e02fed448c}
+: ${GNULIB_REVISION=72abb08f4495bf232736f4d13a24bced72a9c327}
 
 # Don't check for translations since we don't have any in Octave yet.
 # This avoids the need for sha1sum or compatible utility in bootstrap.
diff --git a/libgui/src/find-files-dialog.cc b/libgui/src/find-files-dialog.cc
index 39516221e3..455759bb30 100644
--- a/libgui/src/find-files-dialog.cc
+++ b/libgui/src/find-files-dialog.cc
@@ -120,7 +120,6 @@ find_files_dialog::find_files_dialog (QWidget *p)
   m_file_list->setSelectionBehavior (QAbstractItemView::SelectRows);
   m_file_list->setSelectionMode (QAbstractItemView::SingleSelection);
   m_file_list->setAlternatingRowColors (true);
-  m_file_list->setToolTip (tr ("Search results"));
   m_file_list->setSortingEnabled (true);
   m_file_list->horizontalHeader ()->restoreState (settings.value (ff_column_state.settings_key ()).toByteArray ());
   m_file_list->horizontalHeader ()->setSortIndicatorShown (true);
@@ -160,7 +159,9 @@ find_files_dialog::find_files_dialog (QWidget *p)
            this, &find_files_dialog::close);
 
   // name options
+  const QString gbox_style_sheet ("QGroupBox { font-weight: bold; } ");
   QGroupBox *name_group = new QGroupBox (tr ("Filename/Location"));
+  name_group->setStyleSheet(gbox_style_sheet);
   QGridLayout *name_layout = new QGridLayout;
   name_group->setLayout (name_layout);
 
@@ -178,6 +179,7 @@ find_files_dialog::find_files_dialog (QWidget *p)
 
   // content options
   QGroupBox *content_group = new QGroupBox (tr ("File contents"));
+  content_group->setStyleSheet(gbox_style_sheet);
   QGridLayout *content_layout = new QGridLayout;
   content_group->setLayout (content_layout);
   content_layout->addWidget (m_contains_text_check, 4, 1);
@@ -185,12 +187,22 @@ find_files_dialog::find_files_dialog (QWidget *p)
   content_layout->setColumnStretch (2, 1);
   content_layout->addWidget (m_content_case_check, 5, 1);
 
+  // results
+  QLabel *results_hint = new QLabel (tr ("Results: Double click opens the file"
+                                         " or sets the directory"));
+  QGroupBox *results_group = new QGroupBox (tr ("Search results"));
+  results_group->setStyleSheet(gbox_style_sheet);
+  QVBoxLayout *results_layout = new QVBoxLayout ();
+  results_group->setLayout (results_layout);
+  results_layout->addWidget (results_hint);
+  results_layout->addWidget (m_file_list);
+
+  // main layout
   QGridLayout *main_layout = new QGridLayout;
-  main_layout->setSizeConstraint (QLayout::SetFixedSize);
   main_layout->addWidget (name_group, 0, 0);
   main_layout->addWidget (content_group, 1, 0);
   main_layout->addWidget (button_box, 0, 1, 3, 1);
-  main_layout->addWidget (m_file_list, 2, 0);
+  main_layout->addWidget (results_group, 2, 0);
   main_layout->setRowStretch (2, 1);
   main_layout->addWidget (m_status_bar, 3, 0, 1, -1);
 
diff --git a/libgui/src/find-files-model.cc b/libgui/src/find-files-model.cc
index 7770071127..2a19bcdb60 100644
--- a/libgui/src/find-files-model.cc
+++ b/libgui/src/find-files-model.cc
@@ -176,6 +176,23 @@ find_files_model::data (const QModelIndex& idx, int role) const
               break;
             }
         }
+      else if (role ==  Qt::ToolTipRole)
+        {
+          switch (idx.column ())
+            {
+            case 0:
+              retval = tr ("Double click to open the file");
+              break;
+
+            case 1:
+              retval = tr ("Double click to set the directory");
+              break;
+
+            default:
+              break;
+            }
+        }
+
     }
 
   return retval;
diff --git a/libinterp/corefcn/gl2ps-print.cc b/libinterp/corefcn/gl2ps-print.cc
index d12665507b..111c3c0476 100644
--- a/libinterp/corefcn/gl2ps-print.cc
+++ b/libinterp/corefcn/gl2ps-print.cc
@@ -40,6 +40,7 @@
 #include <gl2ps.h>
 
 #include "file-ops.h"
+#include "filepos-wrappers.h"
 #include "lo-mappers.h"
 #include "oct-locbuf.h"
 #include "oct-env.h"
@@ -419,7 +420,7 @@ gl2ps_renderer::draw (const graphics_object& go, const std::string& print_cmd)
           m_buffer_overflow = false;
           buffsize *= 2;
 
-          std::fseek (tmpf, 0, SEEK_SET);
+          octave_fseeko_wrapper (tmpf, 0, SEEK_SET);
           octave_ftruncate_wrapper (fileno (tmpf), 0);
 
           // For LaTeX output the print process uses 2 drawnow() commands.
@@ -493,7 +494,7 @@ gl2ps_renderer::draw (const graphics_object& go, const std::string& print_cmd)
         }
 
       // Copy temporary file to pipe
-      std::fseek (tmpf, 0, SEEK_SET);
+      octave_fseeko_wrapper (tmpf, 0, SEEK_SET);
       char str[8192];  // 8 kB is a common kernel buffersize
       std::size_t nread, nwrite;
       nread = 1;
diff --git a/libinterp/dldfcn/__glpk__.cc b/libinterp/dldfcn/__glpk__.cc
index d042edd46c..8655b64cf6 100644
--- a/libinterp/dldfcn/__glpk__.cc
+++ b/libinterp/dldfcn/__glpk__.cc
@@ -88,6 +88,7 @@ glpk (int sense, int n, int m, double *c, int nz, int *rn, int *cn,
 {
   int typx = 0;
   int errnum = 0;
+  int tout = 0;  // to save and restore msglev settings
 
   time = 0.0;
   status = -1;    // Initialize status to "bad" value
@@ -173,6 +174,10 @@ glpk (int sense, int n, int m, double *c, int nz, int *rn, int *cn,
 
   glp_load_matrix (lp, nz, rn, cn, a);
 
+  // sort the constraints for better presolving analogue to the code
+  // sample provided by glpk
+  glp_sort_matrix (lp);
+
   if (save_pb)
     {
       static char tmp[] = "outpb.lp";
@@ -180,6 +185,12 @@ glpk (int sense, int n, int m, double *c, int nz, int *rn, int *cn,
         error ("__glpk__: unable to write problem");
     }
 
+  // direct calling glp_subroutines requires explicit msglev setting
+  if (par.msglev < 3)
+    tout = glp_term_out (GLP_OFF);
+  else
+    tout = glp_term_out (GLP_ON);
+
   // scale the problem data
   if (! par.presol || lpsolver != 1)
     glp_scale_prob (lp, scale);
@@ -188,6 +199,8 @@ glpk (int sense, int n, int m, double *c, int nz, int *rn, int *cn,
   if (lpsolver == 1 && ! par.presol)
     glp_adv_basis (lp, 0);
 
+  glp_term_out (tout);  // restore previous msglev status
+
   // For MIP problems without a presolver, a first pass with glp_simplex
   // is required
   if ((! isMIP && lpsolver == 1)
@@ -586,8 +599,8 @@ Undocumented internal function.
   OCTAVE_GLPK_GET_REAL_PARAM ("toldj", par.toldj);
 
   // Relative tolerance used to choose eligible pivotal elements of
-  //  the simplex table in the ratio test
-  par.tolpiv = 1e-10;
+  // the simplex table in the ratio test
+  par.tolpiv = 1e-9;
   OCTAVE_GLPK_GET_REAL_PARAM ("tolpiv", par.tolpiv);
 
   par.objll = -std::numeric_limits<double>::max ();
diff --git a/libinterp/octave-value/ov-base-int.h b/libinterp/octave-value/ov-base-int.h
index f7fb347a82..87f0af867a 100644
--- a/libinterp/octave-value/ov-base-int.h
+++ b/libinterp/octave-value/ov-base-int.h
@@ -58,9 +58,13 @@ class OCTINTERP_TEMPLATE_API octave_base_int_matrix : public octave_base_matrix<
 {
 public:
 
-  octave_base_int_matrix () : octave_base_matrix<T> () { }
+  OCTINTERP_OVERRIDABLE_FUNC_API octave_base_int_matrix ()
+  : octave_base_matrix<T> ()
+  { }
 
-  octave_base_int_matrix (const T& nda) : octave_base_matrix<T> (nda) { }
+  OCTINTERP_OVERRIDABLE_FUNC_API octave_base_int_matrix (const T& nda)
+  : octave_base_matrix<T> (nda)
+  { }
 
   ~octave_base_int_matrix () = default;
 
diff --git a/scripts/optimization/glpk.m b/scripts/optimization/glpk.m
index 194e281285..e2c9acd3d6 100644
--- a/scripts/optimization/glpk.m
+++ b/scripts/optimization/glpk.m
@@ -318,7 +318,7 @@
 ## feasible.  It is not recommended that you change this parameter unless you
 ## have a detailed understanding of its purpose.
 ##
-## @item tolpiv (default: 1e-10)
+## @item tolpiv (default: 1e-9)
 ## Relative tolerance used to choose eligible pivotal elements of the simplex
 ## table.  It is not recommended that you change this parameter unless you have
 ## a detailed understanding of its purpose.