[sankaku] support '/posts/' URLs (#4688)

gallery_dl/extractor/sankaku.py

@@ -143,7 +143,7 @@ class SankakuPostExtractor(SankakuExtractor):
     """Extractor for single posts from sankaku.app"""
     subcategory = "post"
     archive_fmt = "{id}"
-    pattern = BASE_PATTERN + r"/post/show/([0-9a-f]+)"
+    pattern = BASE_PATTERN + r"/post(?:s|/show)/([0-9a-f]+)"
     example = "https://sankaku.app/post/show/12345"
 
     def __init__(self, match):

test/results/sankaku.py

@@ -147,6 +147,18 @@ __tests__ = (
     "md5": "f8ba89043078f0e4be2d9c46550b840a",
 },
 
+{
+    "#url"     : "https://chan.sankakucomplex.com/posts/f8ba89043078f0e4be2d9c46550b840a",
+    "#comment" : "/posts/ instead of /post/show/ (#4688)",
+    "#category": ("booru", "sankaku", "post"),
+    "#class"   : sankaku.SankakuPostExtractor,
+    "#pattern" : r"https://s\.sankakucomplex\.com/data/f8/ba/f8ba89043078f0e4be2d9c46550b840a\.jpg",
+    "#count"   : 1,
+
+    "id" : 33195194,
+    "md5": "f8ba89043078f0e4be2d9c46550b840a",
+},
+
 {
     "#url"     : "https://chan.sankakucomplex.com/post/show/360451",
     "#category": ("booru", "sankaku", "post"),