[deviantart:stash] fix legacy sta.sh links (#7181)

follow redirect instead of rewriting them to deviantart.com/stash/…

gallery_dl/extractor/deviantart.py

@@ -1004,7 +1004,7 @@ class DeviantartStashExtractor(DeviantartExtractor):
     """Extractor for sta.sh-ed deviations"""
     subcategory = "stash"
     archive_fmt = "{index}.{extension}"
-    pattern = (r"(?:https?://)?(?:(?:www\.)?deviantart\.com/stash|sta\.sh)"
+    pattern = (r"(?:https?://)?(?:(?:www\.)?deviantart\.com/stash|sta\.s(h))"
                r"/([a-z0-9]+)")
     example = "https://www.deviantart.com/stash/abcde"
 
@@ -1016,9 +1016,18 @@ class DeviantartStashExtractor(DeviantartExtractor):
 
     def deviations(self, stash_id=None):
         if stash_id is None:
-            stash_id = self.groups[0]
-        url = "https://www.deviantart.com/stash/" + stash_id
-        page = self._limited_request(url).text
+            legacy_url, stash_id = self.groups
+        else:
+            legacy_url = False
+
+        if legacy_url and stash_id[0] == "2":
+            url = "https://sta.sh/" + stash_id
+            response = self._limited_request(url)
+            stash_id = response.url.rpartition("/")[2]
+            page = response.text
+        else:
+            url = "https://www.deviantart.com/stash/" + stash_id
+            page = self._limited_request(url).text
 
         if stash_id[0] == "0":
             uuid = text.extr(page, '//deviation/', '"')

test/results/deviantart.py

@@ -389,6 +389,19 @@ __tests__ = (
     "#url"     : "https://sta.sh/022c83odnaxc",
     "#category": ("", "deviantart", "stash"),
     "#class"   : deviantart.DeviantartStashExtractor,
+    "#pattern" : r"https://wixmp-ed30a86b8c4ca887773594c2.wixmp.com/f/940f2d05-c5eb-4917-8192-7eb6a2d508c6/dcvdmbc-e506cdcf-3208-4c20-85ab-0bfa8a7bcb16.png\?token=ey.+",
+    "#count"   : 1,
+
+    "date"          : "dt:2018-12-26 14:49:27",
+    "deviationid"   : "A4A6AD52-8857-46EE-ABFE-86D49D4FF9D0",
+    "download_filesize": 380,
+    "extension"     : "png",
+    "filename"      : "01_by_justatest235723-dcvdmbc",
+    "index"         : 778297656,
+    "index_base36"  : "cvdmbc",
+    "published_time": 1545835767,
+    "title"         : "01",
+    "url"           : "https://www.deviantart.com/stash/022c83odnaxc",
 },
 
 {