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| author |  Joey Hess <joeyh@joeyh.name> | 2017-09-12 15:13:42 -0400 |
|---|---|---|
| committer | Joey Hess <joeyh@joeyh.name> | 2017-09-12 15:13:42 -0400 |
| commit | fa78a0d811c2ee7d2be608722e38af643c6a036b (patch) | |
| tree | 2a2cbffe3a56323458ca371149655152c48de7e5 | |
| parent | c2dd2a28a55709d598fef4e05ac7bfd6291479b5 (diff) | |
deal with box.com horrible infinite redirect behavior
webdav: Checking if a non-existent file is present on Box.com triggered a
bug in its webdav support that generates an infinite series of redirects.
It seems to redirect foo to foo/ to foo/index.php to
foo/index.php/index.php ... Why a webdav endpoint would behave this way
who knows.
Deal with such problems by assuming such behavior means the file is not
present.
Can't simply disable following redirects, because the webdav endpoint could
legitimately be redirected to a new endpoint. So, when this happens
10 redirects have to be followed, before it gives up and assumes this means
the file does not exist.
This commit was supported by the NSF-funded DataLad project.
| -rw-r--r-- | CHANGELOG | 4 | ||||
| -rw-r--r-- | Remote/WebDAV.hs | 10 | ||||
| -rw-r--r-- | Utility/Url.hs | 7 |
3 files changed, 18 insertions, 3 deletions
@@ -10,6 +10,10 @@ git-annex (6.20170819) UNRELEASED; urgency=medium * init: Display an additional message when it detects a filesystem that allows writing to files whose write bit is not set. * S3: Allow removing files from IA. + * webdav: Checking if a non-existent file is present on Box.com + triggered a bug in its webdav support that generates an infinite series + of redirects. Deal with such problems by assuming such behavior means + the file is not present. -- Joey Hess <id@joeyh.name> Mon, 28 Aug 2017 12:20:59 -0400 diff --git a/Remote/WebDAV.hs b/Remote/WebDAV.hs index 04eb35cef..12b9d40b2 100644 --- a/Remote/WebDAV.hs +++ b/Remote/WebDAV.hs @@ -32,7 +32,7 @@ import Remote.Helper.Export import qualified Remote.Helper.Chunked.Legacy as Legacy import Creds import Utility.Metered -import Utility.Url (URLString, matchStatusCodeException) +import Utility.Url (URLString, matchStatusCodeException, matchHttpExceptionContent) import Annex.UUID import Remote.WebDAV.DavLocation @@ -317,11 +317,15 @@ existsDAV l = inLocation l check `catchNonAsync` (\e -> return (Left $ show e)) -- more depth is certainly not needed to check if a -- location exists. setDepth (Just Depth1) - catchJust - (matchStatusCodeException (== notFound404)) + catchJust missinghttpstatus (getPropsM >> ispresent True) (const $ ispresent False) ispresent = return . Right + missinghttpstatus e = + matchStatusCodeException (== notFound404) e + <|> matchHttpExceptionContent toomanyredirects e + toomanyredirects (TooManyRedirects _) = True + toomanyredirects _ = False safely :: DAVT IO a -> DAVT IO (Maybe a) safely = eitherToMaybe <$$> tryNonAsync diff --git a/Utility/Url.hs b/Utility/Url.hs index e1a21af5d..e6dcd3388 100644 --- a/Utility/Url.hs +++ b/Utility/Url.hs @@ -27,6 +27,7 @@ module Utility.Url ( downloadQuiet, parseURIRelaxed, matchStatusCodeException, + matchHttpExceptionContent, ) where import Common @@ -365,3 +366,9 @@ matchStatusCodeException want e@(StatusCodeException s _ _) | otherwise = Nothing matchStatusCodeException _ _ = Nothing #endif + +matchHttpExceptionContent :: (HttpExceptionContent -> Bool) -> HttpException -> Maybe HttpException +matchHttpExceptionContent want e@(HttpExceptionRequest _ hec) + | want hec = Just e + | otherwise = Nothing +matchHttpExceptionContent _ _ = Nothing |