fix inconsistent use of symlink mtimes in database;

on upload, dupes are by default handled by symlinking to the existing
copy on disk, writing the uploader's local mtime into the symlink mtime,
which is also what gets indexed in the db

this worked as intended, however during an -e2dsa rescan on startup the
symlink destination timestamps would be used instead, causing a reindex
and the resulting loss of uploader metadata (ip, timestamp)

will now always use the symlink's mtime;
worst-case 1% slower startup (no dhash)

this change will cause a reindex of incorrectly indexed files, however
as this has already happened at least once due to the bug being fixed,
there will be no additional loss of metadata

copyparty/up2k.py

@@ -1050,7 +1050,7 @@ def _build_dir(
         if WINDOWS:
             rd = rd.replace("\\", "/").strip("/")
 
-        g = statdir(self.log_func, not self.args.no_scandir, False, cdir)
+        g = statdir(self.log_func, not self.args.no_scandir, True, cdir)
         gl = sorted(g)
         partials = set([x[0] for x in gl if "PARTIAL" in x[0]])
         for iname, inf in gl:
@@ -1065,6 +1065,12 @@ def _build_dir(
                 continue
 
             lmod = int(inf.st_mtime)
+            if stat.S_ISLNK(inf.st_mode):
+                try:
+                    inf = bos.stat(abspath)
+                except:
+                    continue
+
             sz = inf.st_size
             if fat32 and not ffat and inf.st_mtime % 2:
                 fat32 = False
@@ -1445,9 +1451,11 @@ def _verify_integrity(self, vol: VFS) -> int:
                 pf = "v{}, {:.0f}+".format(n_left, b_left / 1024 / 1024)
                 self.pp.msg = pf + abspath
 
-                st = bos.stat(abspath)
+                # throws on broken symlinks (always did)
+                stl = bos.lstat(abspath)
+                st = bos.stat(abspath) if stat.S_ISLNK(stl.st_mode) else stl
+                mt2 = int(stl.st_mtime)
                 sz2 = st.st_size
-                mt2 = int(st.st_mtime)
 
                 if nohash or not sz2:
                     w2 = up2k_wark_from_metadata(self.salt, sz2, mt2, rd, fn)
@@ -1469,6 +1477,13 @@ def _verify_integrity(self, vol: VFS) -> int:
                 if w == w2:
                     continue
 
+                # symlink mtime was inconsistent before v1.9.4; check if that's it
+                if st != stl and (nohash or not sz2):
+                    mt2b = int(st.st_mtime)
+                    w2b = up2k_wark_from_metadata(self.salt, sz2, mt2b, rd, fn)
+                    if w == w2b:
+                        continue
+
                 rewark.append((drd, dfn, w2, sz2, mt2))
 
                 t = "hash mismatch: {}\n  db: {} ({} byte, {})\n  fs: {} ({} byte, {})"