fully support relocatable binaries, improving AppImages

* You can now specify `--with-scitecodatadir` as a relative path,
  that will be interpreted relative to the binary's location.
* Win32 binaries already were relocatable, but this was a Windows-specific
  hack. Win32 binaries are now built with `--with-scitecodatadir=.`
  since everything is in a single directory.
* Ubuntu packages are now also built `--with-scitecodatadir=../share/sciteco`.
  This is not crucial for ordinary installations, but is meant for AppImage creation.
* Since AppImages are now built from relocatable packages,
  we no longer need the unionfs-workaround from pkg2appimage.
  This should fix the strange root contents when autocompleting in
  AppImage builds.
* This might also fix the appimage.github.io CI issues.
  I assume that because I could reproduce the issue on FreeBSD's
  Linuxulator in dependence of pkg2appimage's "union"-setting.
  See AppImage/appimage.github.io#3402
* Determining the binary location actually turned out be hard and
  very platform-dependant. There are now implementations for Windows
  (which could also read argv[0]), Linux and generic UNIX (which
  works on FreeBSD, but I am not sure about the others).
  I believe this could also be useful on Mac OS to create app bundles,
  but this needs to be tested - currently the Mac OS binaries are
  installed into fixed locations and don't use relocation.

.github/workflows/nightly.yml

@@ -218,9 +218,11 @@ jobs:
         mkdir build-wingui build-wincon
         (cd build-wingui
          ../configure --with-interface=pdcurses-gui --enable-html-manual --program-prefix=g \
+                      --with-scitecodatadir=. \
                       PDCURSES_LIBS="-lpdcurses_wingui -lgdi32 -lcomdlg32 -lwinmm")
         (cd build-wincon
          ../configure --with-interface=pdcurses --enable-html-manual \
+                      --with-scitecodatadir=. \
                       PDCURSES_LIBS="-lpdcurses_wincon -lgdi32 -lwinmm")
 
     - name: make
@@ -244,9 +246,10 @@ jobs:
       run: |
         mkdir temp-bin/
         cd temp-bin/
-        cp /mingw32/bin/{gsciteco.exe,sciteco.exe,grosciteco.tes,tedoc.tes} ./
-        cp -r /mingw32/share/sciteco/{lib,*.tmac} ./
-        cp /mingw32/share/sciteco/sample.teco_ini .teco_ini
+        cp -r /mingw32/bin/{gsciteco.exe,sciteco.exe,grosciteco.tes,tedoc.tes} ./
+        # datadir is relative to bindir
+        cp -r /mingw32/bin/{lib,*.tmac} ./
+        cp /mingw32/bin/sample.teco_ini .teco_ini
         cp -r /mingw32/share/doc/sciteco/* ./
         cp ../COPYING ../ChangeLog ./
         cp /mingw32/bin/gspawn-win32-helper*.exe ./
@@ -300,7 +303,8 @@ jobs:
         LDFLAGS: -flto
       run: |
         autoreconf -i
-        ./configure --with-interface=gtk --enable-html-manual
+        ./configure --with-interface=gtk --enable-html-manual \
+                    --with-scitecodatadir=.
 
     - name: make
       run: make -j 2
@@ -317,11 +321,12 @@ jobs:
         mkdir temp-bin
         cd temp-bin
         cp /mingw32/bin/{sciteco.exe,grosciteco.tes,tedoc.tes} ./
-        cp -r /mingw32/share/sciteco/{lib,*.tmac} ./
+        # datadir is relative to bindir
+        cp -r /mingw32/bin/{lib,*.tmac} ./
         # FIXME: Maybe there should be a separate win32/.teco_ini with
         # a few pre-enabled settings?
-        cp /mingw32/share/sciteco/sample.teco_ini .teco_ini
-        cp /mingw32/share/sciteco/fallback.css .teco_css
+        cp /mingw32/bin/sample.teco_ini .teco_ini
+        cp /mingw32/bin/fallback.css .teco_css
         cp -r /mingw32/share/doc/sciteco/* ./
         cp ../COPYING ../ChangeLog ./
         cp /mingw32/bin/gspawn-win32-helper*.exe ./

AppImage/curses.yml

@@ -1,10 +1,5 @@
 app: sciteco-curses
 
-# We currently use paths hardcoded at build-time.
-# Alternatively, it would be possible to customize the AppRun script or
-# add a wrapper that sets $SCITECOPATH.
-union: true
-
 ingredients:
   packages:
     - sciteco-curses

AppImage/gtk.yml

@@ -1,10 +1,5 @@
 app: sciteco-gtk
 
-# We currently use paths hardcoded at build-time.
-# Alternatively, it would be possible to customize the AppRun script or
-# add a wrapper that sets $SCITECOPATH.
-union: true
-
 ingredients:
   packages:
     - sciteco-gtk

TODO

@@ -466,11 +466,6 @@ Features:
  * Get into mentors.debian.net. First step to being adopted
    into the Debian repositories.
  * Get meta-rhaberkorn into https://layers.openembedded.org
- * Linux: Relocatable binaries instead of hardcoding the library path.
-   This makes it possible to run builds installed via
-   `make install DESTDIR=...` and will aid in creating AppImages.
-   Currently we have to define "union: true" and consequently
-   the root directory is not what we would expect.
  * sample.teco_ini: Support opening files on certain lines
    (filename:line).
    Theoretically, this could also be added to the <EB> syntax,

configure.ac

@@ -173,29 +173,38 @@ AC_CHECK_FUNCS([memset setlocale strchr strrchr fstat sscanf], , [
 # glib defines G_OS_UNIX instead...
 case $host in
 *-*-linux* | *-*-*bsd* | *-*-darwin* | *-*-cygwin* | *-*-haiku*)
-	AC_CHECK_FUNCS([realpath fchown dup dup2 getpid open read kill mmap], , [
+	AC_CHECK_FUNCS([realpath readlink fchown dup dup2 getpid open read kill mmap], , [
 		AC_MSG_ERROR([Missing libc function])
 	])
+	AC_SEARCH_LIBS(dladdr, [dl], , [
+		AC_MSG_ERROR([No library providing dladdr()!])
+	])
 	;;
 esac
 
 #
 # Config options
 #
 
+# NOTE: This can be relative to the binary location for relocateable builds.
 AC_ARG_WITH(scitecodatadir,
 	AS_HELP_STRING([--with-scitecodatadir=PATH],
 	               [Installation directory of data [default=DATADIR/sciteco]]),
-	[scitecodatadir=$withval], [scitecodatadir=$datadir/$PACKAGE])
+	[scitecodatadir_rel=$withval], [scitecodatadir_rel=$datadir/$PACKAGE])
+AC_SUBST(scitecodatadir_rel)
+# The Automake installation directory needs to be absolute, though:
+case "$scitecodatadir_rel" in
+/*) scitecodatadir="$scitecodatadir_rel";;
+*)  scitecodatadir="$bindir/$scitecodatadir_rel";;
+esac
 AC_SUBST(scitecodatadir)
 # SciTECO library macro directory
 scitecolibdir=$scitecodatadir/lib
 AC_SUBST(scitecolibdir)
 
 # These paths can be changed at install-time and
 # should not be written into config.h:
-AM_CPPFLAGS="$AM_CPPFLAGS -D'SCITECODATADIR=\"\$(scitecodatadir)\"' \
-                          -D'SCITECOLIBDIR=\"\$(scitecolibdir)\"'"
+AM_CPPFLAGS="$AM_CPPFLAGS -D'SCITECODATADIR=\"\$(scitecodatadir_rel)\"'"
 
 # FIXME: It does not really make sense to have this configurable.
 # It would make more sense to allow linking against an externally-provided

debian/rules

@@ -31,11 +31,15 @@ endif
 
 build build-arch build-indep: build-curses-stamp build-gtk-stamp;
 
+# NOTE: The datadir will be relative to the binary location at runtime.
+# This makes the binary relocateable, which is important when creating
+# AppImages from the Debian packages.
 build-curses-stamp:
 	dh_testdir
 	rm -rf build-curses
 	dh_auto_configure -Bbuild-curses -- \
-	                  --with-interface=ncurses
+	                  --with-interface=ncurses \
+	                  --with-scitecodatadir=../share/sciteco
 	dh_auto_build -Bbuild-curses
 	dh_auto_test -Bbuild-curses
 	touch $@
@@ -47,7 +51,8 @@ build-gtk-stamp:
 	rm -rf build-gtk
 	dh_auto_configure -Bbuild-gtk -- \
 	                  --program-prefix=g \
-	                  --with-interface=gtk
+	                  --with-interface=gtk \
+	                  --with-scitecodatadir=../share/sciteco
 # NOTE: Since the Gtk+ version of SciTECO is called during the build,
 # we need an XServer which may be missing on the build server.
 # That's why we use xvfb.

distribute.mk.in

@@ -110,6 +110,7 @@ mingw-binary : @PACKAGE@-@[email protected]
 	 PKG_CONFIG_LIBDIR=/usr/i686-w64-mingw32/lib/pkgconfig \
 	 ./configure --host=i686-w64-mingw32 build=i386-pc-linux-gnu \
 	             --prefix=/usr \
+	             --with-scitecodatadir=. \
 	             --enable-static-executables \
 	             --disable-dependency-tracking \
 		     --with-interface=$(MINGW_UI) \
@@ -122,11 +123,11 @@ mingw-binary : @PACKAGE@-@[email protected]
 		install-strip DESTDIR=`pwd`/temp-install
 	rm -rf $(SCITECO_DIR)/
 	mkdir temp-bin/
-	cp -r temp-install/usr/bin/* temp-install/usr/share/sciteco/* \
+	cp -r temp-install/usr/bin/* \
 	      temp-install/usr/share/doc/sciteco/* \
 	   temp-bin/
 	cp @srcdir@/win32.teco_ini temp-bin/.teco_ini || \
-		cp temp-install/usr/share/sciteco/sample.teco_ini \
+		cp temp-install/usr/bin/sample.teco_ini \
 		   temp-bin/.teco_ini
 	cp @srcdir@/COPYING @srcdir@/ChangeLog temp-bin/
 	rm -rf temp-install/

src/file-utils.c

@@ -19,6 +19,7 @@
 #include "config.h"
 #endif
 
+#define _GNU_SOURCE
 #include <limits.h>
 #include <stdlib.h>
 #include <string.h>
@@ -35,6 +36,10 @@
 #include <glib.h>
 #include <glib/gstdio.h>
 
+#ifdef G_OS_UNIX
+#include <dlfcn.h>
+#endif
+
 #include "sciteco.h"
 #include "qreg.h"
 #include "interface.h"
@@ -179,6 +184,86 @@ teco_file_is_visible(const gchar *path)
 
 #endif /* !G_OS_WIN32 */
 
+#ifdef G_OS_WIN32
+
+gchar *
+teco_file_get_program_path(void)
+{
+	TCHAR buf[MAX_PATH];
+	if (!GetModuleFileNameW(NULL, buf, G_N_ELEMENTS(buf))
+		return g_get_current_dir();
+	g_autofree gchar *exe = g_utf16_to_utf8(buf, -1, NULL, NULL, NULL);
+	return g_path_get_dirname(exe);
+}
+
+#elif defined(__linux__)
+
+gchar *
+teco_file_get_program_path(void)
+{
+	gchar buf[PATH_MAX];
+	ssize_t len = readlink("/proc/self/exe", buf, sizeof(buf)-1);
+	if (G_UNLIKELY(len < 0))
+		/* almost certainly wrong */
+		return g_get_current_dir();
+	buf[len] = '\0';
+
+	return g_path_get_dirname(buf);
+}
+
+#elif defined(G_OS_UNIX)
+
+/*
+ * At least works on FreeBSD, even though it also has
+ * sysctl(KERN_PROC_PATHNAME).
+ * We assume it works on all other UNIXes as well.
+ */
+gchar *
+teco_file_get_program_path(void)
+{
+	Dl_info info;
+	return dladdr(teco_file_get_program_path, &info)
+		? g_path_get_dirname(info.dli_fname) : g_get_current_dir();
+}
+
+#else /* !G_OS_WIN32 && !__linux__ && !G_OS_UNIX */
+
+/*
+ * This is almost guaranteed to be wrong,
+ * meaning that SciTECO cannot be made relocatable on these platforms.
+ * It may be worth evaluating argv[0] on these platforms.
+ */
+gchar *
+teco_file_get_program_path(void)
+{
+	return g_get_current_dir();
+}
+
+#endif
+
+/**
+ * Get the datadir.
+ *
+ * By default it is hardcoded to an absolute path at
+ * build time.
+ * However, you can also build relocateable binaries
+ * where the datadir is relative to the program's executable.
+ *
+ * @note Beginning with glib v2.58, we could directly use
+ * g_canonicalize_filename().
+ */
+gchar *
+teco_file_get_datadir(void)
+{
+	if (g_path_is_absolute(SCITECODATADIR))
+		return g_strdup(SCITECODATADIR);
+
+	/* relocateable binary - datadir is relative to binary */
+	g_autofree gchar *program_path = teco_file_get_program_path();
+	g_autofree gchar *datadir = g_build_filename(program_path, SCITECODATADIR, NULL);
+	return teco_file_get_absolute_path(datadir);
+}
+
 /**
  * Perform tilde expansion on a file name or path.
  *

src/file-utils.h

@@ -68,6 +68,18 @@ teco_file_normalize_path(gchar *path)
 
 gboolean teco_file_is_visible(const gchar *path);
 
+/**
+ * Get absolute path of the program executable.
+ *
+ * This may return the current working directory on
+ * unsupported platforms.
+ *
+ * @return Newly-allocated path.
+ */
+gchar *teco_file_get_program_path(void);
+
+gchar *teco_file_get_datadir(void);
+
 gchar *teco_file_expand_path(const gchar *path);
 
 /**

src/interface-gtk/interface.c

@@ -51,6 +51,7 @@
 #include "sciteco.h"
 #include "error.h"
 #include "string-utils.h"
+#include "file-utils.h"
 #include "cmdline.h"
 #include "qreg.h"
 #include "ring.h"
@@ -1124,6 +1125,8 @@ teco_interface_event_loop(GError **error)
 	}
 	g_assert(scitecoconfig.data != NULL);
 
+	g_autofree gchar *datadir = teco_file_get_datadir();
+
 	/*
 	 * Initialize the CSS variable provider and the CSS provider
 	 * for the included fallback.css.
@@ -1138,14 +1141,7 @@ teco_interface_event_loop(GError **error)
 	if (!g_file_test(user_css_file, G_FILE_TEST_IS_REGULAR)) {
 		/* use fallback CSS */
 		g_free(user_css_file);
-		/*
-		 * FIXME: See above for icons.
-		 */
-#ifdef G_OS_WIN32
-		user_css_file = g_build_filename(scitecoconfig.data, "fallback.css", NULL);
-#else
-		user_css_file = g_build_filename(SCITECODATADIR, "fallback.css", NULL);
-#endif
+		user_css_file = g_build_filename(datadir, "fallback.css", NULL);
 	}
 
 	GtkCssProvider *user_css_provider = gtk_css_provider_new();
@@ -1170,33 +1166,27 @@ teco_interface_event_loop(GError **error)
 	/*
 	 * FIXME: This is necessary so that the icon themes are found in the same
 	 * directory as sciteco.exe.
-	 * This fails of course when $SCITECOCONFIG is changed.
-	 * We should perhaps always use the absolute path of sciteco.exe.
-	 * If you want to install SciTECO differently, you can still set
-	 * $XDG_DATA_DIRS.
-	 *
-	 * FIXME FIXME FIXME: This is also currently broken.
 	 */
-	//g_autofree char *theme_path = g_build_filename(scitecoconfig.data, "icons");
-	//gtk_icon_theme_prepend_search_path(gtk_icon_theme_get_default(), theme_path);
+	g_autofree gchar *program_path = teco_file_get_program_path();
+	g_autofree gchar *theme_path = g_build_filename(program_path, "icons", NULL);
+	gtk_icon_theme_prepend_search_path(gtk_icon_theme_get_default(), theme_path);
 #else
 	/*
 	 * Load icons for the GTK window.
 	 * This is not necessary on Windows since the icon included
 	 * as a resource will be used by default.
 	 */
 	static const gchar *icon_files[] = {
-		SCITECODATADIR G_DIR_SEPARATOR_S "sciteco-48.png",
-		SCITECODATADIR G_DIR_SEPARATOR_S "sciteco-32.png",
-		SCITECODATADIR G_DIR_SEPARATOR_S "sciteco-16.png"
+		"sciteco-48.png", "sciteco-32.png", "sciteco-16.png"
 	};
 	GList *icon_list = NULL;
 
 	for (gint i = 0; i < G_N_ELEMENTS(icon_files); i++) {
-		GdkPixbuf *icon_pixbuf = gdk_pixbuf_new_from_file(icon_files[i], NULL);
+		g_autofree gchar *icon_file = g_build_filename(datadir, icon_files[i], NULL);
+		GdkPixbuf *icon_pixbuf = gdk_pixbuf_new_from_file(icon_file, NULL);
 
 		/* fail silently if there's a problem with one of the icons */
-		if (icon_pixbuf)
+		if (G_LIKELY(icon_pixbuf != NULL))
 			icon_list = g_list_append(icon_list, icon_pixbuf);
 	}