reinject: Added --guesskeys option

Sponsored-by: Noam Kremen on Patreon

CHANGELOG

@@ -1,3 +1,9 @@
+git-annex (10.20230627) UNRELEASED; urgency=medium
+
+  * reinject: Added --guesskeys option.
+
+ -- Joey Hess <id@joeyh.name>  Mon, 26 Jun 2023 13:10:40 -0400
+
 git-annex (10.20230626) upstream; urgency=medium
 
   * Split out two new commands, git-annex pull and git-annex push.

Command/Reinject.hs

@@ -29,6 +29,7 @@ cmd = withAnnexOptions [backendOption, jsonOptions] $
 data ReinjectOptions = ReinjectOptions
 	{ params :: CmdParams
 	, knownOpt :: Bool
+	, guessKeysOpt :: Bool
 	}
 
 optParser :: CmdParamsDesc -> Parser ReinjectOptions
@@ -39,9 +40,16 @@ optParser desc = ReinjectOptions
 		<> help "inject all known files"
 		<> hidden
 		)
+	<*> switch
+		( long "guesskeys"
+		<> help "inject files that are named like keys"
+		<> hidden
+		)
 
 seek :: ReinjectOptions -> CommandSeek
 seek os
+	| guessKeysOpt os && knownOpt os = giveup "Cannot combine --known with --guesskeys"
+	| guessKeysOpt os = withStrings (commandAction . startGuessKeys) (params os)
 	| knownOpt os = withStrings (commandAction . startKnown) (params os)
 	| otherwise = withPairs (commandAction . startSrcDest) (params os)
 
@@ -66,6 +74,24 @@ startSrcDest (si, (src, dest))
 	src' = toRawFilePath src
 	ai = ActionItemOther (Just (QuotedPath src'))
 
+startGuessKeys :: FilePath -> CommandStart
+startGuessKeys src = starting "reinject" ai si $ notAnnexed src' $
+	case fileKey (toRawFilePath (takeFileName src)) of
+		Just key -> ifM (verifyKeyContent key src')
+			( perform src' key
+			, do
+				qp <- coreQuotePath <$> Annex.getGitConfig
+				giveup $ decodeBS $ quote qp $ QuotedPath src'
+					<> " does not have expected content"
+			)
+		Nothing -> do
+			warning "Not named like an object file; skipping"
+			next $ return True
+  where
+	src' = toRawFilePath src
+	ai = ActionItemOther (Just (QuotedPath src'))
+	si = SeekInput [src]
+
 startKnown :: FilePath -> CommandStart
 startKnown src = starting "reinject" ai si $ notAnnexed src' $ do
 	(key, _) <- genKey ks nullMeterUpdate =<< defaultBackend

doc/git-annex-reinject.mdwn

@@ -54,6 +54,20 @@ needing to specify the dest file.
   Specify the key-value backend to use when checking if a file is known
   with the `--known` option.
 
+* `--guesskeys`
+
+  With this option, each specified source file is checked to see if it
+  has the name of a git-annex key, and if so it is imported as the content
+  of that key.
+
+  This can be used to pluck git-annex objects out of `lost+found`,
+  as long as the original filename has not been lost,
+  and is particularly useful when using key-value backends that don't hash
+  to the content of a file.
+
+  When the key-value backend does support hashing, the content of the file
+  is verified before importing it.
+
 * `--json`
 
   Enable JSON output. This is intended to be parsed by programs that use