--- a/doc/doxyhtml/Doxyfile.in	Wed Mar 14 22:26:31 2018 -0700
+++ b/doc/doxyhtml/Doxyfile.in	Wed Mar 14 22:49:19 2018 -0700
@@ -40,7 +40,7 @@
 # This tag specifies the encoding used for all characters in the config file
 # that follow. The default is UTF-8 which is also the encoding used for all text
 # before the first occurrence of this tag. Doxygen uses libiconv (or the iconv
-# built into libc) for the transcoding. See http://www.gnu.org/software/libiconv
+# built into libc) for the transcoding. See https://www.gnu.org/software/libiconv
 # for the list of possible encodings.
 # The default value is: UTF-8.
 
@@ -385,7 +385,7 @@
 # This tag can be used to specify the character encoding of the source files
 # that doxygen parses. Internally doxygen uses the UTF-8 encoding. Doxygen uses
 # libiconv (or the iconv built into libc) for the transcoding. See the libiconv
-# documentation (see: http://www.gnu.org/software/libiconv) for the list of
+# documentation (see: https://www.gnu.org/software/libiconv) for the list of
 # possible encodings.
 # The default value is: UTF-8.
 

--- a/doc/interpreter/install.txi	Wed Mar 14 22:26:31 2018 -0700
+++ b/doc/interpreter/install.txi	Wed Mar 14 22:49:19 2018 -0700
@@ -125,13 +125,13 @@
 The Octave sources are primarily written in C++, but some portions are
 also written in C and Fortran.  The Octave sources are intended to be
 portable.  Recent versions of the GNU compiler collection (GCC) should
-work (@url{http://gcc.gnu.org}).  If you use GCC, you should avoid
+work (@url{https://gcc.gnu.org}).  If you use GCC, you should avoid
 mixing versions.  For example, be sure that you are not using the
 obsolete @code{g77} Fortran compiler with modern versions of @code{gcc}
 and @code{g++}.
 
 @item GNU Make
-Tool for building software (@url{http://www.gnu.org/software/make}).
+Tool for building software (@url{https://www.gnu.org/software/make}).
 Octave's build system requires GNU Make.  Other versions of Make will
 not work.  Fortunately, GNU Make is highly portable and easy to install.
 
@@ -145,40 +145,40 @@
 
 @table @asis
 @item Bison
-Parser generator (@url{http://www.gnu.org/software/bison}).
+Parser generator (@url{https://www.gnu.org/software/bison}).
 You will need Bison if you modify the @code{oct-parse.yy} source file or
 if you delete the files that are generated from it.
 
 @item Flex
-Lexer analyzer (@url{http://www.gnu.org/software/flex}).  You will need
+Lexer analyzer (@url{https://www.gnu.org/software/flex}).  You will need
 Flex if you modify the @code{lex.ll} source file or if you delete the
 files that are generated from it.
 
 @item Autoconf
 Package for software configuration
-(@url{http://www.gnu.org/software/autoconf}).  Autoconf is required if
+(@url{https://www.gnu.org/software/autoconf}).  Autoconf is required if
 you modify Octave's @code{configure.ac} file or other files that it
 requires.
 
 @item Automake
 Package for Makefile generation
-(@url{http://www.gnu.org/software/automake}).  Automake is required if
+(@url{https://www.gnu.org/software/automake}).  Automake is required if
 you modify Octave's @code{Makefile.am} files or other files that they
 depend on.
 
 @item Libtool
 Package for building software libraries
-(@url{http://www.gnu.org/software/libtool}).  Libtool is required by
+(@url{https://www.gnu.org/software/libtool}).  Libtool is required by
 Automake.
 
 @item gperf
-Perfect hash function generator (@url{http://www.gnu.org/software/gperf}).
+Perfect hash function generator (@url{https://www.gnu.org/software/gperf}).
 You will need gperf if you modify the @code{octave.gperf} file or if you
 delete the file that is generated from it.
 
 @item Texinfo
 Package for generating online and print documentation
-(@url{http://www.gnu.org/software/texinfo}).  You will need Texinfo to
+(@url{https://www.gnu.org/software/texinfo}).  You will need Texinfo to
 build Octave's documentation or if you modify the documentation source
 files or the docstring of any Octave function.
 @end table
@@ -246,7 +246,7 @@
 to perform font rendering for Octave's OpenGL-based graphics functions.
 
 @item GLPK
-GNU Linear Programming Kit (@url{http://www.gnu.org/software/glpk}).
+GNU Linear Programming Kit (@url{https://www.gnu.org/software/glpk}).
 GPLK is required for the function @code{glpk}.
 
 @item @nospell{gl2ps}

--- a/libgui/src/m-editor/find-dialog.cc	Wed Mar 14 22:26:31 2018 -0700
+++ b/libgui/src/m-editor/find-dialog.cc	Wed Mar 14 22:49:19 2018 -0700
@@ -38,7 +38,7 @@
 ** Foundation and appearing in the file LICENSE.LGPL included in the
 ** packaging of this file.  Please review the following information to
 ** ensure the GNU Lesser General Public License version 2.1 requirements
-** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+** will be met: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
 **
 ** In addition, as a special exception, Nokia gives you certain additional
 ** rights.  These rights are described in the Nokia Qt LGPL Exception
@@ -50,7 +50,7 @@
 ** Foundation and appearing in the file LICENSE.GPL included in the
 ** packaging of this file.  Please review the following information to
 ** ensure the GNU General Public License version 3.0 requirements will be
-** met: http://www.gnu.org/copyleft/gpl.html.
+** met: https://www.gnu.org/copyleft/gpl.html.
 **
 ** If you have questions regarding the use of this file, please contact
 ** Nokia at qt-info@nokia.com.

--- a/libgui/src/m-editor/find-dialog.h	Wed Mar 14 22:26:31 2018 -0700
+++ b/libgui/src/m-editor/find-dialog.h	Wed Mar 14 22:49:19 2018 -0700
@@ -38,7 +38,7 @@
 ** Foundation and appearing in the file LICENSE.LGPL included in the
 ** packaging of this file.  Please review the following information to
 ** ensure the GNU Lesser General Public License version 2.1 requirements
-** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+** will be met: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
 **
 ** In addition, as a special exception, Nokia gives you certain additional
 ** rights.  These rights are described in the Nokia Qt LGPL Exception
@@ -50,7 +50,7 @@
 ** Foundation and appearing in the file LICENSE.GPL included in the
 ** packaging of this file.  Please review the following information to
 ** ensure the GNU General Public License version 3.0 requirements will be
-** met: http://www.gnu.org/copyleft/gpl.html.
+** met: https://www.gnu.org/copyleft/gpl.html.
 **
 ** If you have questions regarding the use of this file, please contact
 ** Nokia at qt-info@nokia.com.

--- a/m4/ax_blas.m4	Wed Mar 14 22:26:31 2018 -0700
+++ b/m4/ax_blas.m4	Wed Mar 14 22:49:19 2018 -0700
@@ -1,5 +1,5 @@
 # ===========================================================================
-#          http://www.gnu.org/software/autoconf-archive/ax_blas.html
+#          https://www.gnu.org/software/autoconf-archive/ax_blas.html
 # ===========================================================================
 #
 # SYNOPSIS

--- a/m4/ax_compare_version.m4	Wed Mar 14 22:26:31 2018 -0700
+++ b/m4/ax_compare_version.m4	Wed Mar 14 22:49:19 2018 -0700
@@ -1,5 +1,5 @@
 # ===========================================================================
-#    http://www.gnu.org/software/autoconf-archive/ax_compare_version.html
+#    https://www.gnu.org/software/autoconf-archive/ax_compare_version.html
 # ===========================================================================
 #
 # SYNOPSIS

--- a/m4/ax_lapack.m4	Wed Mar 14 22:26:31 2018 -0700
+++ b/m4/ax_lapack.m4	Wed Mar 14 22:49:19 2018 -0700
@@ -1,5 +1,5 @@
 # ===========================================================================
-#         http://www.gnu.org/software/autoconf-archive/ax_lapack.html
+#         https://www.gnu.org/software/autoconf-archive/ax_lapack.html
 # ===========================================================================
 #
 # SYNOPSIS

--- a/m4/ax_openmp.m4	Wed Mar 14 22:26:31 2018 -0700
+++ b/m4/ax_openmp.m4	Wed Mar 14 22:49:19 2018 -0700
@@ -1,5 +1,5 @@
 # ===========================================================================
-#         http://www.gnu.org/software/autoconf-archive/ax_openmp.html
+#         https://www.gnu.org/software/autoconf-archive/ax_openmp.html
 # ===========================================================================
 #
 # SYNOPSIS

--- a/m4/ax_pthread.m4	Wed Mar 14 22:26:31 2018 -0700
+++ b/m4/ax_pthread.m4	Wed Mar 14 22:49:19 2018 -0700
@@ -1,5 +1,5 @@
 # ===========================================================================
-#        http://www.gnu.org/software/autoconf-archive/ax_pthread.html
+#        https://www.gnu.org/software/autoconf-archive/ax_pthread.html
 # ===========================================================================
 #
 # SYNOPSIS

--- a/m4/octave_blas_f77_func.m4	Wed Mar 14 22:26:31 2018 -0700
+++ b/m4/octave_blas_f77_func.m4	Wed Mar 14 22:49:19 2018 -0700
@@ -6,7 +6,7 @@
 # match the size of integers used by the BLAS library.
 
 # ===========================================================================
-#     http://www.gnu.org/software/autoconf-archive/ax_blas_f77_func.html
+#     https://www.gnu.org/software/autoconf-archive/ax_blas_f77_func.html
 # ===========================================================================
 #
 # SYNOPSIS

--- a/scripts/strings/native2unicode.m	Wed Mar 14 22:26:31 2018 -0700
+++ b/scripts/strings/native2unicode.m	Wed Mar 14 22:49:19 2018 -0700
@@ -28,7 +28,7 @@
 ## @var{codepage} must be an identifier of a valid code page.  Examples for
 ## valid code pages are @qcode{"ISO-8859-1"}, @qcode{"Shift-JIS"}, or
 ## @qcode{"UTF-16"}.  For a list of supported code pages, see
-## @url{http://www.gnu.org/software/libiconv}.  If @var{codepage} is omitted
+## @url{https://www.gnu.org/software/libiconv}.  If @var{codepage} is omitted
 ## or empty, the system default codepage is used.
 ##
 ## If @var{native_bytes} is a string vector, it is returned as is.

--- a/scripts/strings/unicode2native.m	Wed Mar 14 22:26:31 2018 -0700
+++ b/scripts/strings/unicode2native.m	Wed Mar 14 22:49:19 2018 -0700
@@ -26,7 +26,7 @@
 ## string @var{codepage} must be an identifier of a valid code page.
 ## Examples for valid code pages are @qcode{"ISO-8859-1"},
 ## @qcode{"Shift-JIS"}, or @qcode{"UTF-16"}.  For a list of supported code
-## pages, see @url{http://www.gnu.org/software/libiconv}.  If @var{codepage}
+## pages, see @url{https://www.gnu.org/software/libiconv}.  If @var{codepage}
 ## is omitted or empty, the system default codepage is used.
 ##
 ## If any of the characters cannot be mapped into the codepage @var{codepage},