From 3392079e4b54dca7830050ee852df70ad66036aa Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Thu, 4 Jan 2024 18:38:28 +0100
Subject: [PATCH] generator: teach generator_add_symlink_full() to optionally
 make alias symlinks rather than just .wants/ style symlinks

---
 src/shared/generator.c | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/src/shared/generator.c b/src/shared/generator.c
index d183eb9654..b96715c59c 100644
--- a/src/shared/generator.c
+++ b/src/shared/generator.c
@@ -80,7 +80,6 @@ int generator_open_unit_file_full(
         return 0;
 }
 
-
 int generator_add_symlink_full(
                 const char *dir,
                 const char *dst,
@@ -93,11 +92,13 @@ int generator_add_symlink_full(
 
         assert(dir);
         assert(dst);
-        assert(dep_type);
         assert(src);
 
-        /* Adds a symlink from <dst>.<dep_type>/ to <src> (if src is absolute) or ../<src> (otherwise). If
-         * <instance> is specified, then <src> must be a template unit name, and we'll instantiate it. */
+        /* If 'dep_type' is specified adds a symlink from <dst>.<dep_type>/ to <src> (if src is absolute) or ../<src> (otherwise).
+         *
+         * If 'dep_type' is NULL, it will create a symlink to <src> (i.e. create an alias.
+         *
+         * If <instance> is specified, then <src> must be a template unit name, and we'll instantiate it. */
 
         r = path_extract_directory(src, &dn);
         if (r < 0 && r != -EDESTADDRREQ) /* EDESTADDRREQ → just a file name was passed */
@@ -115,11 +116,19 @@ int generator_add_symlink_full(
                         return log_error_errno(r, "Failed to instantiate '%s' for '%s': %m", fn, instance);
         }
 
-        from = path_join(dn ?: "..", fn);
-        if (!from)
-                return log_oom();
+        if (dep_type) { /* Create a .wants/ style dep */
+                from = path_join(dn ?: "..", fn);
+                if (!from)
+                        return log_oom();
 
-        to = strjoin(dir, "/", dst, ".", dep_type, "/", instantiated ?: fn);
+                to = strjoin(dir, "/", dst, ".", dep_type, "/", instantiated ?: fn);
+        } else { /* or create an alias */
+                from = dn ? path_join(dn, fn) : strdup(fn);
+                if (!from)
+                        return log_oom();
+
+                to = strjoin(dir, "/", dst);
+        }
         if (!to)
                 return log_oom();