try retrieval from more than one export location when the first fails

Combined with commit 0ffc59d34107a3ee671b90fc7c59ca09c00abbf5, this
fixes the case where there are duplicate files on the special remote,
and the first gets modified/deleted, while the second is still present.

directory, adb: Fixed a bug when importtree=yes, and multiple files in the
special remote have the same content, that caused it to refuse to get a
file from the special remote, incorrectly complaining that it had changed,
due to only accepting the inode+mtime of one file (that was since modified
or deleted) and not accepting the inode+mtime of other duplicate files.

Sponsored-by: Max Thoursie on Patreon

diff --git a/CHANGELOG b/CHANGELOG
index 6c6f009293735478965c5666b2633a03fdab3e1a..c054007290bc6d2c73576eb9a1e44d7c77dedb82 100644 (file)
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -17,6 +17,12 @@ git-annex (10.20220823) UNRELEASED; urgency=medium
     ignoreinode setting has been changed. When getting a file from such a
     remote, accept the content that would have been accepted with the
     previous ignoreinode setting.
+  * directory, adb: Fixed a bug when importtree=yes, and multiple files
+    in the special remote have the same content, that caused it to
+    refuse to get a file from the special remote, incorrectly complaining
+    that it had changed, due to only accepting the inode+mtime of one file
+    (that was since modified or deleted) and not accepting the inode+mtime
+    of other duplicate files.
 
  -- Joey Hess <id@joeyh.name>  Mon, 29 Aug 2022 15:03:04 -0400
 

diff --git a/Remote/Helper/ExportImport.hs b/Remote/Helper/ExportImport.hs
index ddccda74dd8f3b2d78b3ace5e221af3814312ccc..1d71ae70d110e423ae4ba63d8336ebe7212e3829 100644 (file)
--- a/Remote/Helper/ExportImport.hs
+++ b/Remote/Helper/ExportImport.hs
@@ -327,11 +327,6 @@ adjustExportImport' isexport isimport r rs = do
                db <- getexportdb dbv
                liftIO $ Export.getExportTree db k
        
-       getfirstexportloc dbv k = do
-               getexportlocs dbv k >>= \case
-                       [] -> giveup "unknown export location"
-                       (l:_) -> return l
-       
        getexportlocs dbv k = do
                db <- getexportdb dbv
                liftIO $ Export.getExportTree db k >>= \case
@@ -340,6 +335,15 @@ adjustExportImport' isexport isimport r rs = do
                                , return []
                                )
                        ls -> return ls
+       
+       tryexportlocs dbv k a = 
+               go Nothing =<< getexportlocs dbv k
+         where
+               go Nothing [] = giveup "unknown export location"
+               go (Just ex) [] = throwM ex
+               go _ (l:ls) = tryNonAsync (a l) >>= \case
+                       Right v -> return v
+                       Left e -> go (Just e) ls
                
        getkeycids ciddbv k = do
                db <- getciddb ciddbv
@@ -350,9 +354,8 @@ adjustExportImport' isexport isimport r rs = do
        -- have replaced with content not of the requested key, the content
        -- has to be strongly verified.
        retrieveKeyFileFromExport dbv k _af dest p = ifM (isVerifiable k)
-               ( do
-                       l <- getfirstexportloc dbv k
-                       retrieveExport (exportActions r) k l dest p >>= return . \case
+               ( tryexportlocs dbv k $ \loc -> 
+                       retrieveExport (exportActions r) k loc dest p >>= return . \case
                                UnVerified -> MustVerify
                                IncompleteVerify iv -> MustFinishIncompleteVerify iv
                                v -> v
@@ -362,9 +365,8 @@ adjustExportImport' isexport isimport r rs = do
        retrieveKeyFileFromImport dbv ciddbv k af dest p = do
                cids <- getkeycids ciddbv k
                if not (null cids)
-                       then do
-                               l <- getfirstexportloc dbv k
-                               snd <$> retrieveExportWithContentIdentifier (importActions r) l cids dest (Left k) p
+                       then tryexportlocs dbv k $ \loc ->
+                               snd <$> retrieveExportWithContentIdentifier (importActions r) loc cids dest (Left k) p
                        -- In case a content identifier is somehow missing,
                        -- try this instead.
                        else if isexport