synchronize gphoto-m4 files

7 files changed, 797 insertions, 17 deletions

diff --git a/gphoto-m4/Makefile-files b/gphoto-m4/Makefile-files
new file mode 100644
index 000000000..bc7ce8eb4
--- /dev/null
+++ b/gphoto-m4/Makefile-files
@@ -0,0 +1,31 @@
+# -*- Makefile -*-
+
+EXTRA_DIST += %reldir%/README.md
+EXTRA_DIST += %reldir%/gphoto-m4-sync
+
+EXTRA_DIST += %reldir%/gp-byteorder.m4
+EXTRA_DIST += %reldir%/gp-camlibs.m4
+EXTRA_DIST += %reldir%/gp-check-doxygen.m4
+EXTRA_DIST += %reldir%/gp-check-library.m4
+EXTRA_DIST += %reldir%/gp-check-popt.m4
+EXTRA_DIST += %reldir%/gp-check-shell-environment.m4
+EXTRA_DIST += %reldir%/gp-config-msg.m4
+EXTRA_DIST += %reldir%/gp-documentation.m4
+EXTRA_DIST += %reldir%/gp-dynamic-libraries.m4
+EXTRA_DIST += %reldir%/gp-gettext-hack.m4
+EXTRA_DIST += %reldir%/gp-internal-docs.m4
+EXTRA_DIST += %reldir%/gp-libltdl.m4
+EXTRA_DIST += %reldir%/gp-manual-docbook-xml.m4
+EXTRA_DIST += %reldir%/gp-manual-documentation.m4
+EXTRA_DIST += %reldir%/gp-manual-fig2dev.m4
+EXTRA_DIST += %reldir%/gp-manual-graphviz.m4
+EXTRA_DIST += %reldir%/gp-manual-gtk-doc.m4
+EXTRA_DIST += %reldir%/gp-manual-pstoimg.m4
+EXTRA_DIST += %reldir%/gp-manual-w3m.m4
+EXTRA_DIST += %reldir%/gp-packaging.m4
+EXTRA_DIST += %reldir%/gp-pkg-config.m4
+EXTRA_DIST += %reldir%/gp-references.m4
+EXTRA_DIST += %reldir%/gp-stdint.m4
+EXTRA_DIST += %reldir%/gp-subpackage.m4
+EXTRA_DIST += %reldir%/gp-udev.m4
+EXTRA_DIST += %reldir%/gp-va-copy.m4
diff --git a/gphoto-m4/Makefile.am b/gphoto-m4/Makefile.am
index 4997e15e8..b69097e76 100644
--- a/gphoto-m4/Makefile.am
+++ b/gphoto-m4/Makefile.am
@@ -1 +1,7 @@
-EXTRA_DIST = gp-byteorder.m4 gp-camlibs.m4 gp-check-doxygen.m4 gp-check-library.m4 gp-check-popt.m4 gp-check-shell-environment.m4 gp-config-msg.m4 gp-documentation.m4 gp-dynamic-libraries.m4 gp-gettext-hack.m4 gp-internal-docs.m4 gp-libltdl.m4 gp-manual-docbook-xml.m4 gp-manual-documentation.m4 gp-manual-fig2dev.m4 gp-manual-graphviz.m4 gp-manual-gtk-doc.m4 gp-manual-pstoimg.m4 gp-manual-w3m.m4 gp-packaging.m4 gp-pkg-config.m4 gp-references.m4 gp-stdint.m4 gp-udev.m4 gp-va-copy.m4 README.m4
+# This is the compatibility Makefile.am - you are probably better off
+# just including the Makefile-files directly from your top-level
+# Makefile.am.
+
+EXTRA_DIST =
+
+include Makefile-files
diff --git a/gphoto-m4/README.m4 b/gphoto-m4/README.m4
deleted file mode 100644
index 57b89fca0..000000000
--- a/gphoto-m4/README.m4
+++ /dev/null
@@ -1,9 +0,0 @@
-This is the gPhoto projects' collection of autoconf/automake m4 macros.
-
-It has been designed to be used in
-  - gphoto2
-  - libgphoto2 
-  - libgphoto2_port (located in libgphoto2/)
-  - gtkam
-
-Some macros are re-used ones from libexif.
diff --git a/gphoto-m4/README.md b/gphoto-m4/README.md
new file mode 100644
index 000000000..b756b23fd
--- /dev/null
+++ b/gphoto-m4/README.md
@@ -0,0 +1,140 @@
+gphoto-m4
+=========
+
+`gphoto-m4` is the gPhoto projects' collection of m4 macros for use
+with the autoconf/automake based build systems.
+
+It has been designed to be used in
+
+  * `gphoto2`
+  * `libgphoto2`
+  * `libgphoto2_port` (located in `libgphoto2/`)
+  * `gtkam`
+
+Some macros are re-used ones from `libexif`.
+
+Since the gPhoto project moved from SVN to git, we have not figured
+out yet how to properly include the `gphoto-m4` files into the
+respective software's `gphoto-m4/` subdirectory (either `git subtree`
+or `git submodule` come to mind).
+
+So for the time being, we manually update and synchronize the files.
+
+
+Use of `gphoto-m4` after the switch to git from SVN
+---------------------------------------------------
+
+Since the gPhoto project moved from SVN to git, we have not figured
+out yet how to properly include the `gphoto-m4` files into the
+respective software's `gphoto-m4/` subdirectory. The options are:
+
+  1. Manually update (and hopefully synchronize) the files.
+
+     Advantages:
+
+       * No special commands needed for users or developers.
+
+     Disadvantages:
+
+       * The manual work for the maintainers is exhausting and error
+         prone.
+
+  2. Use `git submodule`.
+
+     Advantages:
+
+       * Defined mechanism for syncing and updating the `gphoto-m4/*`
+         files.
+
+     Disadvantages:
+
+       * Requires special git commands from everybody (users,
+         developers, and maintainers) all the time (e.g. `git clone
+         --recursive` instead of `git clone`).
+
+         This is the showstopper for `git submodule`.
+
+  3. Use `git subtree`.
+
+     Advantages:
+
+       * Defined mechanism for syncing and updating the `gphoto-m4/*`
+         files.
+
+       * Requires no special git commands from users or developers.
+
+       * Not even people actually messing with the files in
+         `gphoto-m4/*` strictly need special commands.
+
+         Only the maintainers who do the syncing and updating of the
+		 `gphoto-m4/*` files need the special commands.
+
+     Disadvantages:
+
+       * Requires special knowledge of special commands instead of
+         just copying files around. The concept is less complex than
+         copying files round, but it does require special commands.
+
+       * No rebasing possible across pulls to `gphoto-m4/`. Not really
+         necessary anyway, though.
+
+       * Pushes of changes to from, say, `gphoto2/gphoto-m4` to
+         upstream `gphoto-m4` create a lot of commit history noise in
+         the `gphoto-m4` repository by including the complete history
+         of the `gphoto2` repository.
+
+         Note this cannot be avoided by using `git subtree split`:
+         That is executed internally by `git subtree push`.
+
+         So it appears that using `git subtree push` will push all
+         projects' commit history into the `gphoto-m4` repo.
+
+         That is if not a showstopper, then at least very ugly.
+
+For the time being, we manually update and synchronize the files.
+
+
+Manually syncing and updating files
+-----------------------------------
+
+This section has not been written yet.
+
+
+Using `git submodule`
+---------------------
+
+This section has not been written yet.
+
+
+Using `git subtree`
+-------------------
+
+
+### Using `gphoto-m4` as git subtree ###
+
+This section describes how to use `gphoto-m4` when it has been set up
+as a `git subtree` (e.g. in `gphoto2` and `libgphoto2`).
+
+Add a remote for `gphoto-m4`:
+
+    git remote add origin-gphoto-m4 git@github.com:gphoto/gphoto-m4.git
+
+Pull changes to origin-gphoto-m4 into local `gphoto-m4`:
+
+    git subtree pull --prefix gphoto-m4 origin-gphoto-m4 master --squash
+
+Now we can push local changes to 'gphoto-m4/*' back to
+`origin-gphoto-m4` as follows:
+
+    git subtree push --prefix gphoto-m4 origin-gphoto-m4 master
+
+FIXME: Add more typical uses cases.
+
+
+### Setting up `gphoto-m4` as git subtree ###
+
+This section describes how we initially set up `gphoto-m4` as a git
+subtree for `gphoto2`. This is only required once by one person, then
+never needs to be done by anybody else ever again.
+
+    git subtree add --prefix gphoto-m4 origin-gphoto-m4 master --squash
diff --git a/gphoto-m4/gp-check-popt.m4 b/gphoto-m4/gp-check-popt.m4
index 9bf506a24..f88f86958 100644
--- a/gphoto-m4/gp-check-popt.m4
+++ b/gphoto-m4/gp-check-popt.m4
@@ -64,8 +64,34 @@ if test "x$POPT_CFLAGS" = "x" && test "x$POPT_LIBS" = "x"; then
 	# try to find options to compile popt.h
 	CPPFLAGS_save="$CPPFLAGS"
 	popth_found=no
-	for popt_prefix in "" /usr /usr/local
-	do
+        case "$MSYSTEM" in
+         MINGW32)
+		if test -n "/mingw32"; then
+			:
+		elif test -d "/mingw32/include"; then
+			CPPFLAGS="-I/mingw32/include ${CPPFLAGS}"
+		else
+			continue
+		fi
+		ac_cv_header_popt_h=""
+		unset ac_cv_header_popt_h
+		AC_CHECK_HEADER([popt.h], [popth_found=yes])
+         ;;
+         MINGW64)
+		if test -n "${popt_prefix}"; then
+			:
+		elif test -d "/mingw64/include"; then
+			CPPFLAGS="-I/mingw64/include ${CPPFLAGS}"
+		else
+			continue
+		fi
+		ac_cv_header_popt_h=""
+		unset ac_cv_header_popt_h
+		AC_CHECK_HEADER([popt.h], [popth_found=yes])
+         ;;
+         *)
+           for popt_prefix in "" /usr /usr/local
+           do
 		if test -n "${popt_prefix}"; then
 			:
 		elif test -d "${popt_prefix}/include"; then
@@ -77,7 +103,9 @@ if test "x$POPT_CFLAGS" = "x" && test "x$POPT_LIBS" = "x"; then
 		unset ac_cv_header_popt_h
 		AC_CHECK_HEADER([popt.h], [popth_found=yes])
 		if test "$popth_found" = yes; then break; fi
-	done
+	   done
+         ;;
+        esac
 	CPPFLAGS="$CPPFLAGS_save"
 	if test "$popth_found" = "yes"; then
 		if test "$popt_prefix" = ""; then
@@ -96,7 +124,38 @@ if test "x$POPT_CFLAGS" = "x" && test "x$POPT_LIBS" = "x"; then
 	# try to find options to link against popt
 	LDFLAGS_save="$LDFLAGS"
 	popt_links=no
-	for popt_prefix in /usr "" /usr/local; do
+        case "$MSYSTEM" in
+         MINGW32)
+#		for ldir in "" lib; do
+			popt_libdir="/mingw32/lib"
+			if test "${popt_libdir}" = "/"; then
+				popt_libdir=""
+			elif test -d "${popt_libdir}"; then
+				LDFLAGS="-L${popt_libdir} ${LDFLAGS}"
+			else
+				continue
+			fi
+			# Avoid caching of results
+			ac_cv_lib_popt_poptStuffArgs=""
+			unset ac_cv_lib_popt_poptStuffArgs
+			AC_CHECK_LIB([popt], [poptStuffArgs], [popt_links=yes])
+         ;;
+         MINGW64)
+			popt_libdir="/mingw64/lib"
+			if test "${popt_libdir}" = "/"; then
+				popt_libdir=""
+			elif test -d "${popt_libdir}"; then
+				LDFLAGS="-L${popt_libdir} ${LDFLAGS}"
+			else
+				continue
+			fi
+			# Avoid caching of results
+			ac_cv_lib_popt_poptStuffArgs=""
+			unset ac_cv_lib_popt_poptStuffArgs
+			AC_CHECK_LIB([popt], [poptStuffArgs], [popt_links=yes])
+          ;;
+         *)
+	    for popt_prefix in /usr "" /usr/local; do
 		# We could have "/usr" and "lib64" at the beginning of the
 		# lists. Then the first tested location would
 		# incidentally be the right one on 64bit systems, and
@@ -124,7 +183,9 @@ if test "x$POPT_CFLAGS" = "x" && test "x$POPT_LIBS" = "x"; then
 			if test "$popt_links" = yes; then break; fi
 		done
 		if test "$popt_links" = yes; then break; fi
-	done
+	  done
+         ;;
+        esac
 	LDFLAGS="$LDFLAGS_save"
 	if test "$popt_links" = "yes"; then
 		if test "$popt_libdir" = ""; then
diff --git a/gphoto-m4/gp-references.m4 b/gphoto-m4/gp-references.m4
index 9ca1e270c..71ff44774 100644
--- a/gphoto-m4/gp-references.m4
+++ b/gphoto-m4/gp-references.m4
@@ -17,9 +17,9 @@ GP_REF(	[URL_GPHOTO_HOME],
 	[http://www.gphoto.org/], 
 	[gphoto project home page])dnl
 
-GP_REF(	[URL_GPHOTO_PROJECT], 
+GP_REF(	[URL_GPHOTO_PROJECT],
 	[https://github.com/gphoto],
-	[gphoto sourceforge project page])
+	[gphoto github project page])
 
 GP_REF(	[URL_DIGICAM_LIST],
 	[http://www.teaser.fr/~hfiguiere/linux/digicam.html],
diff --git a/gphoto-m4/gphoto-m4-sync b/gphoto-m4/gphoto-m4-sync
new file mode 100755
index 000000000..f324d4dfc
--- /dev/null
+++ b/gphoto-m4/gphoto-m4-sync
@@ -0,0 +1,551 @@
+#!/usr/bin/env python3
+#
+# Usage: gphoto-m4-sync [--diff] <dir>...
+#        gphoto-m4-sync --help
+#
+# The gphoto-m4-sync script helps with keeping track of which files in
+# which gphoto-m4 tree copy differ from the original gphoto-m4 tree.
+#
+# In normal operation, gphoto-m4-sync will search for gphoto-m4
+# directories anywhere in the directory trees given on the command
+# line and compare the gphoto-m4 tree from which gphoto-m4-sync was
+# started to those other trees.
+#
+# When not given a --diff options, gphoto-m4-sync will print a human
+# readable report on which files are different in which gphoto-m4
+# tree.
+#
+# Options:
+#
+#   --diff   Print a list of 'diff' command lines to compare
+#            the different files instead. Pipe into something like
+#            "| sh | less" to execute.
+#
+#   --help   Print this help message.
+#
+# Exit code:
+#
+#   0    when no  differences have been found among the gphoto-m4 trees
+#   1    when any differences have been found among the gphoto-m4 trees
+#   2    any other error
+
+
+########################################################################
+
+
+import hashlib
+import os
+import sys
+
+
+########################################################################
+
+
+class File(object):
+
+    def __init__(self, tree, fname):
+        self.tree = tree
+        self.fname = fname
+        self.fpath = os.path.join(tree.top, fname)
+
+        self.statinfo = os.stat(self.fpath)
+
+        m = hashlib.sha1()
+        m.update(open(self.fpath, 'rb').read())
+        self.digest = m.hexdigest()
+
+    def __repr__(self):
+        return 'File(%s,%s)' % (repr(self.fname), repr(self.digest))
+
+    def __str__(self):
+        return '%s %s' % (self.digest, self.fname)
+
+
+########################################################################
+
+
+class BaseTree(object):
+
+    def __init__(self, top):
+        self.top = os.path.abspath(top)
+        self._files = self.__scan_files()
+
+    def __repr__(self):
+        return '%s(%s)[%s]' % (self.__class__.__name__, self.top, self._files)
+
+    def __iter__(self):
+        return sorted(self._files).__iter__()
+
+    def __getitem__(self, key):
+        return self._files[key]
+
+    def __scan_files(self):
+        files = {}
+        for dirpath, dirnames, filenames in os.walk(self.top, topdown=True):
+            try: # do not descend into these directories
+                dirnames.remove('.git')
+            except ValueError:
+                pass
+
+            for fname in filenames:
+                # Ignore a bunch of files
+                if fname[-1] == '~':
+                    continue
+                if fname.startswith('.git'):
+                    continue
+                if fname in ['Makefile.in', 'Makefile']:
+                    continue
+
+                abs_fname = os.path.join(dirpath, fname)
+                rel_fname = os.path.relpath(abs_fname, start=self.top)
+
+                files[rel_fname] = File(self, rel_fname)
+        return files
+
+
+########################################################################
+
+
+class GitTree(BaseTree):
+
+    def __init__(self, top):
+        path = os.path.join(top, '.git')
+        if not os.path.exists(path):
+            raise AssertionError("File or directory does not exist: %s" %
+                                 repr(path))
+        super(GitTree, self).__init__(top)
+
+
+########################################################################
+
+
+class NotGitTree(BaseTree):
+
+    def __init__(self, top):
+        path = os.path.join(top, '.git')
+        if os.path.exists(path):
+            raise AssertionError("File or directory does exist: %s" %
+                                 repr(path))
+        super(NotGitTree, self).__init__(top)
+
+
+########################################################################
+
+
+def scan_tree(top):
+    for dirpath, dirnames, filenames in os.walk(top):
+        if os.path.basename(dirpath) == 'gphoto-m4':
+            if 'gp-camlibs.m4' not in filenames:
+                continue
+            yield (dirpath, NotGitTree(dirpath))
+
+
+########################################################################
+
+
+def print_help():
+    skip_line = True
+    skip_lines = ['#', '# ']
+    for line in open(__file__, 'r'):
+        if line[-1] == '\n':
+            line = line[:-1]
+
+        if line.startswith('#!'):
+            continue
+        elif skip_line and (line in skip_lines):
+            continue
+        elif skip_line and (line not in skip_lines):
+            skip_line = False
+        elif line == '':
+            break
+
+        if not skip_line:
+            print(line[2:])
+
+
+########################################################################
+
+
+class ResultTable(object):
+
+    def __init__(self):
+        self.lines = {}
+        self.files_with_differences = 0
+        self.differences = 0
+
+    def __setitem__(self, key, value):
+        assert(key not in self.lines)
+        self.lines[key] = value
+        if value.file_versions > 0:
+            self.files_with_differences += 1
+        self.differences += value.file_versions
+
+    def __getitem__(self, key):
+        assert(self.files_with_differences != None)
+        return self.lines[key]
+
+    def items(self):
+        for k in sorted(self.lines.keys()):
+            v = self.lines[k]
+            yield k,v
+
+    def close(self):
+        pass
+
+
+########################################################################
+
+
+class ResultLine(object):
+
+    def __init__(self, fname):
+        self.fname = fname
+
+        self.__digest_map = {}
+        self.__digests = {}
+        self.__digest_list = None
+
+        self.__flags = {}
+
+        self.__fpaths = {}
+
+    def set_digest(self, index, digest):
+        self.__digest_map[index] = digest
+        self.__digests[digest] = True
+
+    def close(self, file_versions):
+        self.file_versions = file_versions
+        self.__digest_list = sorted(self.__digests.keys())
+        assert(len(self.__digest_list) > 0)
+        if file_versions == 0:
+            # All files are equal, so we do not need different characters
+            # to distinguish different digest values - a space will do as
+            # well.
+            self.__digest_map = {}
+
+    def get_digest(self, index):
+        if self.__digest_list == None:
+            raise RuntimeError("You need to call ResultLine.close() before Result_Line.get_digest()")
+        if index in self.__digest_map:
+            dig = self.__digest_map[index]
+            idx = self.__digest_list.index(dig)
+            return 'abcdefghijklmnopqrstuvwxyz'[idx]
+        else:
+            return ' '
+
+    def set_flag(self, index, flag, fpath):
+        self.__flags[index] = flag
+        self.__fpaths[index] = fpath
+
+    def get_flag(self, index):
+        return self.__flags[index]
+
+    def get_fpath(self, index):
+        return self.__fpaths[index]
+
+
+########################################################################
+
+
+def cmd_print_report(result_table, all_files, treelist, trees):
+    # Enumerate list of trees
+    print("Trees (0 is the original tree):")
+    for i, tree in enumerate(treelist):
+        print("  %d. %s" % (i,tree))
+    print()
+
+    # Determine maximum length of file name
+    fn_maxlen = 0
+    for fn in all_files:
+        if len(fn) > fn_maxlen:
+            fn_maxlen = len(fn)
+
+    fmt = "    %%-%ds " % fn_maxlen
+    print("File table:")
+
+    # print table head
+    print(fmt % '', end='')
+    print((' {0:-^%d}' % (3*len(treelist)-1)).format('Tree'))
+    print(fmt % 'file name', end='')
+    for i, tree in enumerate(treelist):
+        print(' %2d' % i, end='')
+    print('  file diffs')
+    sep_line = ('    ' +
+                '-' * (fn_maxlen + 1 + 3*len(treelist) + 2 + len('file diffs')))
+    print(sep_line)
+
+    # print table body
+    for fname in sorted(all_files):
+        result_line = result_table[fname]
+        print(fmt % fname, end='')
+        print(" %s%s" % (result_line.get_flag(0),
+                         result_line.get_digest(0)), end='')
+
+        for tree_idx, tree_top in enumerate(sorted(trees.keys()), start=1):
+            tree = trees[tree_top]
+            print(" %s%s" % (result_line.get_flag(tree_idx),
+                             result_line.get_digest(tree_idx)), end='')
+
+        if result_line.file_versions > 0:
+            print('   %3d' % result_line.file_versions)
+        else:
+            print('  ok')
+    print(sep_line)
+    print()
+
+    print("Legend:")
+    legend = [
+        ('N', 'new file'),
+        ('O', 'original file'),
+        ('/', 'no such file'),
+        ('=', 'same content as the original file'),
+        ('<', 'file with different content is younger than original file'),
+        ('>', 'file with different content is older than original file'),
+    ]
+    for ch, descr in legend:
+        print("    %s  %s" % (ch, descr))
+    print("    ")
+    print("    Small letters identify file contents: Same letter means same content.")
+    print()
+
+    # Determine exit code
+    exit_code = 0
+    if result_table.differences > 0:
+        exit_code = 1
+
+    # Print summary
+    print("Summary:")
+    if result_table.differences > 0:
+        print("  About %d difference(s) found in %d file(s)." %
+              (result_table.differences, result_table.files_with_differences))
+        print("  ")
+        print("  Diff commands for comparing differing files can be obtained with the")
+        print("  '--diff' option.")
+    else:
+        print("  All gphoto-m4 trees are equal.")
+
+    # Finally exit.
+    sys.exit(exit_code)
+
+
+########################################################################
+
+
+def print_diff_commands(diff_commands):
+    print("#!/bin/sh")
+    print("#")
+    print("# This file has been autogenerated by %s" % __file__)
+    print("#")
+    print("# List of diff commands.  You can pipe these into")
+    print("#     | sh | colordiff | less -r '+/comparing '")
+    print("# or")
+    print("#     | sh | less '+/^comparing '")
+    print("# or")
+    print("#     | less")
+    for fname, orig_dig, other_dig, orig_fpath, other_fpath in diff_commands:
+        if orig_fpath:
+            orig_label = "%s (digest '%s')" % (orig_fpath, orig_dig)
+        else:
+            orig_fpath = '/dev/null'
+            orig_label = '(no such file)'
+
+        if other_dig:
+            other_label = "%s (digest '%s')" % (other_fpath, other_dig)
+        else:
+            other_label = other_fpath
+
+        print()
+        print("""echo 'comparing fname %s'""" % fname)
+        print("""diff -u --label "%s" %s --label "%s" %s"""
+              % (orig_label, orig_fpath,
+                 other_label, other_fpath))
+
+
+########################################################################
+
+
+def gphoto_m4_sync(dir_list, print_diffs):
+
+    # List all files in this clone of the `gphoto-m4` repository
+    orig_top = os.path.dirname(os.path.abspath(__file__))
+    orig_tree = GitTree(orig_top)
+
+    # For each `gphoto-m4` directory given on the command line, find
+    # all files.
+    trees = {}
+    for top in dir_list:
+        for dirpath, tree in scan_tree(os.path.abspath(top)):
+            trees[dirpath] = tree
+
+    if len(trees) == 0:
+        print("No gphoto-m4 trees found in directories given on command line.")
+        sys.exit(2)
+
+
+    # Make a list of all files within all `gphoto-m4` trees
+    all_files = {}
+    for i in orig_tree:
+        all_files[i] = True
+    for tree in trees.values():
+        for i in tree:
+            all_files[i] = True
+    all_files = sorted(all_files.keys())
+
+    # calculate table values
+    diff_params = []
+    result_table = ResultTable()
+    for fname in sorted(all_files):
+        result_line = ResultLine(fname)
+        file_diffs = 0
+        if fname in orig_tree:
+            result_line.set_flag(0, 'O', orig_tree[fname].fpath)
+            orig_dig = orig_tree[fname].digest
+            result_line.set_digest(0, orig_dig)
+        else:
+            result_line.set_flag(0, '/', None)
+            orig_dig = None
+
+        comp_digs = {}
+        for tree_idx, tree_top in enumerate(sorted(trees.keys()), start=1):
+            tree = trees[tree_top]
+            if fname in tree:
+                dig = tree[fname].digest
+                flag = 'N'
+                if orig_dig == dig:
+                    flag = '='
+                elif orig_dig:
+                    if tree[fname].statinfo.st_mtime > orig_tree[fname].statinfo.st_mtime:
+                        flag = '>'
+                    elif tree[fname].statinfo.st_mtime < orig_tree[fname].statinfo.st_mtime:
+                        flag = '<'
+                result_line.set_digest(tree_idx, dig)
+            else:
+                flag = '/'
+
+            if fname in tree:
+                _fpath = tree[fname].fpath
+            else:
+                _fpath = None
+            result_line.set_flag(tree_idx, flag, _fpath)
+
+            if orig_dig:
+                if result_line.get_flag(tree_idx) != '=':
+                    file_diffs += 1
+            else:
+                if result_line.get_flag(tree_idx) != '/':
+                    file_diffs += 1
+
+        result_line.close(file_diffs)
+        del file_diffs
+        result_table[fname] = result_line
+    result_table.close()
+
+    if False:
+        # Diff all files - (some comparisons are unnecessary)
+        for fname in sorted(all_files):
+            result_line = result_table[fname]
+            orig_dig = result_line.get_digest(0)
+            orig_fpath = result_line.get_fpath(0)
+            for tree_idx, tree_top in enumerate(sorted(trees.keys()), start=1):
+                tree = trees[tree_top]
+                if result_line.get_flag(0) == 'O':
+                    if result_line.get_flag(tree_idx) not in ['=', '/']:
+                        diff_params.append((fname,
+                                            orig_fpath, orig_dig,
+                                            result_line.get_fpath(tree_idx),
+                                            result_line.get_digest(tree_idx)))
+                else:
+                    if result_line.get_flag(tree_idx) != '/':
+                        diff_params.append((fname,
+                                            None, None,
+                                            result_line.get_fpath(tree_idx),
+                                            None))
+
+    # Print report
+    if not print_diffs:
+        cmd_print_report(result_table, all_files,
+                         [orig_top] + sorted(trees.keys()),
+                         trees)
+
+    # Print diffs
+    if print_diffs:
+        # print("# Calculate minimum set of diff commands:")
+        diff_commands = []
+        for fname, result_line in result_table.items():
+            line_flags = []
+            if result_line.file_versions > 0:
+                # print("#   -", fname)
+                all_trees = [orig_tree] + [ trees[k] for k in sorted(trees.keys()) ]
+                for idx_a in range(len(all_trees)):
+                    tree_a = all_trees[idx_a]
+                    dig_a = result_line.get_digest(idx_a)
+                    if dig_a == ' ':
+                        continue
+                    # print("# tree_a", tree_a)
+                    for idx_b in range(len(all_trees)):
+                        tree_b = all_trees[idx_b]
+                        dig_b = result_line.get_digest(idx_b)
+                        if dig_a == dig_b:
+                            continue
+                        if dig_b == ' ':
+                            continue
+                        # print("# tree_b", tree_b)
+                        flag     = (fname, dig_a, dig_b)
+                        rev_flag = (fname, dig_b, dig_a)
+                        if flag in line_flags:
+                            pass
+                        elif rev_flag in line_flags:
+                            pass
+                        else:
+                            line_flags.append(flag)
+                            cmd = (fname, dig_a, dig_b,
+                                   tree_a[fname].fpath, tree_b[fname].fpath)
+                            diff_commands.append(cmd)
+                    break
+            del line_flags
+        # print("#")
+
+        print_diff_commands(diff_commands)
+        sys.exit(0)
+
+
+#######################################################################
+
+
+def main(args):
+    if (args == []):
+        print_help()
+        sys.exit(0)
+
+    arg_diff = False
+    for i, arg in enumerate(args):
+        if arg == '--':
+            i += 1
+            break
+        elif arg == '--help':
+            print_help()
+            sys.exit(0)
+        elif arg == '--diff':
+            arg_diff = True
+        elif arg.startswith('--'):
+            raise ValueError("Unhandled command line option '%s'" % arg)
+        else:
+            assert(arg[:2] != '--')
+            break
+
+    dir_list = args[i:]
+    if False:
+        print("Arguments:", dir_list)
+        print()
+
+    gphoto_m4_sync(dir_list, arg_diff)
+
+
+########################################################################
+
+
+if __name__ == '__main__':
+    main(sys.argv[1:])
+
+
+########################################################################