Add independent update mode for symbolic links

.github/workflows/build-publish.yml

@@ -0,0 +1,27 @@
+name: Build & publish
+on: {push: {branches: [master]}, pull_request: {branches: [master]}, workflow_dispatch}
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        fetch-depth: '0'
+    - id: debianise
+      uses: twojstaryzdomu/debianise@HEAD
+      with:
+        create_changelog: true
+        install_build_depends: false
+        debug: true
+    - id: action-gh-release
+      uses: softprops/action-gh-release@v1
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      with:
+        files: ${{ steps.debianise.outputs.files }}
+        name: ${{ steps.debianise.outputs.release_name }}
+        tag_name: ${{ steps.debianise.outputs.tag_name }}
+        fail_on_unmatched_files: true
+        draft: true
+        prerelease: true

debian/compat

@@ -0,0 +1 @@
+11

debian/control

@@ -0,0 +1,16 @@
+Source: rsync
+Section: unknown
+Priority: optional
+Maintainer: unknown <pi@>
+Build-Depends: debhelper (>= 11)
+Standards-Version: 4.1.3
+Homepage: https://github.com/twojstaryzdomu/rsync
+Vcs-Git: https://github.com/twojstaryzdomu/rsync.git
+Vcs-Browser: https://github.com/twojstaryzdomu/rsync
+
+
+Package: rsync
+Section: unknown
+Architecture: any
+Depends: ${shlibs:Depends}, ${misc:Depends}
+Description: rsync description

debian/patches/disable_reconfigure_req.diff

@@ -0,0 +1,38 @@
+diff --git a/Makefile.in b/Makefile.in
+index 3cde955..ef71d7e 100644
+--- a/Makefile.in
++++ b/Makefile.in
+@@ -210,15 +210,6 @@ configure.sh config.h.in: configure.ac aclocal.m4
+ 	else \
+ 	    echo "config.h.in has CHANGED."; \
+ 	fi
+-	@if test -f configure.sh.old || test -f config.h.in.old; then \
+-	    if test "$(MAKECMDGOALS)" = reconfigure; then \
+-		echo 'Continuing with "make reconfigure".'; \
+-	    else \
+-		echo 'You may need to run:'; \
+-		echo '  make reconfigure'; \
+-		exit 1; \
+-	    fi \
+-	fi
+
+ .PHONY: reconfigure
+ reconfigure: configure.sh
+@@ -232,17 +223,6 @@ restatus:
+ Makefile: Makefile.in config.status configure.sh config.h.in
+ 	@if test -f Makefile; then cp -p Makefile Makefile.old; else touch Makefile.old; fi
+ 	@./config.status
+-	@if diff Makefile Makefile.old >/dev/null 2>&1; then \
+-	    echo "Makefile is unchanged."; \
+-	    rm Makefile.old; \
+-	else \
+-	    if test "$(MAKECMDGOALS)" = reconfigure; then \
+-		echo 'Continuing with "make reconfigure".'; \
+-	    else \
+-		echo "Makefile updated -- rerun your make command."; \
+-		exit 1; \
+-	    fi \
+-	fi
+
+ stunnel-rsyncd.conf: $(srcdir)/stunnel-rsyncd.conf.in Makefile
+ 	sed 's;\@bindir\@;$(bindir);g' <$(srcdir)/stunnel-rsyncd.conf.in >stunnel-rsyncd.conf

debian/patches/series

@@ -0,0 +1 @@
+disable_reconfigure_req.diff

debian/rules

@@ -0,0 +1,3 @@
+#!/usr/bin/make -f
+%:
+	dh $@

debian/watch

@@ -0,0 +1,3 @@
+version=4
+opts=filenamemangle=s/.+\/v?(\d\S+)\.tar\.gz/rsync-$1\.tar\.gz/ \
+  https://github.com/twojstaryzdomu/rsync/releases .*/v?(\d\S+)\.tar\.gz

flist.c

@@ -62,6 +62,7 @@ extern int implied_dirs;
 extern int ignore_perishable;
 extern int non_perishable_cnt;
 extern int prune_empty_dirs;
+extern int update_links;
 extern int copy_links;
 extern int copy_unsafe_links;
 extern int protocol_version;
@@ -234,10 +235,15 @@ static int readlink_stat(const char *path, STRUCT_STAT *stp, char *linkbuf)
 int link_stat(const char *path, STRUCT_STAT *stp, int follow_dirlinks)
 {
 #ifdef SUPPORT_LINKS
-	if (copy_links)
+	if (copy_links && update_links == 0)
 		return x_stat(path, stp, NULL);
 	if (x_lstat(path, stp, NULL) < 0)
 		return -1;
+	if (update_links && S_ISLNK(stp->st_mode)) {
+		STRUCT_STAT st;
+		if (x_stat(path, &st, NULL) == 0 && !S_ISDIR(st.st_mode))
+			return 0;
+	}
 	if (follow_dirlinks && S_ISLNK(stp->st_mode)) {
 		STRUCT_STAT st;
 		if (x_stat(path, &st, NULL) == 0 && S_ISDIR(st.st_mode))

generator.c

@@ -57,6 +57,9 @@ extern int ignore_errors;
 extern int remove_source_files;
 extern int delay_updates;
 extern int update_only;
+extern int update_links;
+extern int copy_links;
+extern int allow_link_update_dir;
 extern int human_readable;
 extern int ignore_existing;
 extern int ignore_non_existing;
@@ -1193,6 +1196,19 @@ static BOOL is_below(struct file_struct *file, struct file_struct *subtree)
 		&& (!implied_dirs_are_missing || f_name_has_prefix(file, subtree));
 }
 
+static BOOL dir_empty(char *dirname) {
+	int n = 3;
+	DIR *dir = opendir(dirname);
+	if (dir == NULL)
+		return -1;
+	while (readdir(dir)) {
+		if (!--n)
+			break;
+	}
+	closedir(dir);
+	return n;
+}
+
 /* Acts on the indicated item in cur_flist whose name is fname.  If a dir,
  * make sure it exists, and has the right permissions/timestamp info.  For
  * all other non-regular files (symlinks, etc.) we create them here.  For
@@ -1540,6 +1556,8 @@ static void recv_generator(char *fname, struct file_struct *file, int ndx,
 	 && hard_link_check(file, ndx, fname, statret, &sx, itemizing, code))
 		goto cleanup;
 #endif
+	if (DEBUG_GTE(GENR, 1))
+		rprintf(FINFO, "%s src mtime=%ld dest mtime=%ld modify_window=%d statret=%d copy_links=%d update_links=%d allow_link_update_dir=%d\n", fname, file->modtime, (long)sx.st.st_mtime, modify_window, statret, copy_links, update_links, allow_link_update_dir);
 
 	if (preserve_links && ftype == FT_SYMLINK) {
 #ifdef SUPPORT_LINKS
@@ -1588,6 +1606,66 @@ static void recv_generator(char *fname, struct file_struct *file, int ndx,
 				fnamecmp = fnamecmpbuf;
 			}
 		}
+		if (statret == 0) {
+			if (update_links > 0) {
+				if (S_ISDIR(sx.st.st_mode) && allow_link_update_dir == 0) {
+					if (INFO_GTE(SKIP, 1))
+						rprintf(FINFO, "symlink \"%s\" is a directory on destination and allow-link-update-dir isn't enabled, skipping\n", fname);
+					goto cleanup;
+				}
+				else {
+					int mtime_offset = sx.st.st_mtime - file->modtime;
+					char *st_mode = S_ISDIR(sx.st.st_mode)
+						      ? "directory"
+						      : S_ISLNK(sx.st.st_mode)
+						      ? "symlink"
+						      : S_ISCHR(sx.st.st_mode)
+						      ? "character device"
+						      : S_ISBLK(sx.st.st_mode)
+						      ? "block device"
+						      : S_ISFIFO(sx.st.st_mode)
+						      ? "named pipe"
+						      : S_ISSOCK(sx.st.st_mode)
+						      ? "socket"
+						      : "file";
+					if (mtime_offset > modify_window) {
+						if (INFO_GTE(SKIP, 1))
+							rprintf(FINFO, "%s \"%s\" is newer by %d sec, skipping\n", st_mode, fname, mtime_offset - modify_window);
+						goto cleanup;
+					}
+					else if (mtime_offset < modify_window) {
+						if (S_ISDIR(sx.st.st_mode)) {
+							if (!dir_empty(fname)) {
+								rprintf(FINFO, "directory %s not empty, skipping\n", fname);
+								goto cleanup;
+							}
+						}
+						if (INFO_GTE(SKIP, 1))
+							rprintf(FINFO, "%s \"%s\" is older by %d sec, updating\n", st_mode, fname, - mtime_offset - modify_window);
+					}
+					else if (S_ISLNK(sx.st.st_mode)) {
+						char lnk[MAXPATHLEN];
+						int llen = do_readlink(fname, lnk, MAXPATHLEN - 1);
+						lnk[llen] = '\0';
+						if (strcmp(lnk, F_SYMLINK(file)) == 0) {
+							if (INFO_GTE(SKIP, 1))
+								rprintf(FINFO, "symlink \"%s\" points to the same referent %s, skipping\n", fname, lnk);
+							goto cleanup;
+						}
+						else if (INFO_GTE(SKIP, 1))
+							rprintf(FINFO, "symlink \"%s\" points to a different referent on source (%s) than destination (%s), updating\n", fname, F_SYMLINK(file), lnk);
+					}
+					else {
+						if (INFO_GTE(SKIP, 1))
+							rprintf(FINFO, "symlink \"%s\" more recent than %s on destination, updating\n", fname, st_mode);
+					}
+				}
+			}
+			else {
+				if (DEBUG_GTE(GENR, 1))
+					rprintf(FINFO, "update-links not enabled for \"%s\"\n, skipping", fname);
+			}
+		}
 		if (atomic_create(file, fname, sl, NULL, MAKEDEV(0, 0), &sx, statret == 0 ? DEL_FOR_SYMLINK : 0)) {
 			set_file_attrs(fname, file, NULL, NULL, 0);
 			if (itemizing) {

options.c

@@ -48,6 +48,8 @@ int whole_file = -1;
 int append_mode = 0;
 int keep_dirlinks = 0;
 int copy_dirlinks = 0;
+int update_links = 0;
+int allow_link_update_dir = 0;
 int copy_links = 0;
 int copy_devices = 0;
 int write_devices = 0;
@@ -693,6 +695,8 @@ static struct poptOption long_options[] = {
   {"no-one-file-system",0, POPT_ARG_VAL,    &one_file_system, 0, 0, 0 },
   {"no-x",             0,  POPT_ARG_VAL,    &one_file_system, 0, 0, 0 },
   {"update",          'u', POPT_ARG_NONE,   &update_only, 0, 0, 0 },
+  {"update-links",     0,  POPT_ARG_NONE,   &update_links, 0, 0, 0 },
+  {"allow-link-update-dir",0,POPT_ARG_NONE, &allow_link_update_dir, 0, 0, 0 },
   {"existing",         0,  POPT_ARG_NONE,   &ignore_non_existing, 0, 0, 0 },
   {"ignore-non-existing",0,POPT_ARG_NONE,   &ignore_non_existing, 0, 0, 0 },
   {"ignore-existing",  0,  POPT_ARG_NONE,   &ignore_existing, 0, 0, 0 },
@@ -1380,6 +1384,8 @@ int parse_arguments(int *argc_p, const char ***argv_p)
 		 * only special cases are returned and listed here. */
 
 		switch (opt) {
+		case 'L':
+			break;
 		case 'V':
 			version_opt_cnt++;
 			break;
@@ -2321,6 +2327,9 @@ int parse_arguments(int *argc_p, const char ***argv_p)
 		parse_filter_str(&filter_list, backup_dir_buf, rule_template(0), 0);
 	}
 
+	if (update_links)
+		preserve_links = 1;
+
 	if (make_backups && !backup_dir)
 		omit_dir_times = -1; /* Implied, so avoid -O to sender. */
 
@@ -2615,7 +2624,7 @@ void server_options(char **args, int *argc_p)
 		argstr[x++] = 'u';
 	if (!do_xfers) /* Note: NOT "dry_run"! */
 		argstr[x++] = 'n';
-	if (preserve_links)
+	if (preserve_links || update_links)
 		argstr[x++] = 'l';
 	if ((xfer_dirs >= 2 && xfer_dirs < 4)
 	 || (xfer_dirs && !recurse && (list_only || (delete_mode && am_sender))))
@@ -2634,6 +2643,11 @@ void server_options(char **args, int *argc_p)
 			if (fuzzy_basis > 1)
 				argstr[x++] = 'y';
 		}
+		if (update_links) {
+			args[ac++] = "--update-links";
+			if (allow_link_update_dir)
+			args[ac++] = "--allow-link-update-dir";
+		}
 	} else {
 		if (copy_links)
 			argstr[x++] = 'L';