cannot run with relative path for METS

[bertsky]

In OCR-D, long ago we moved away from absolute filenames and file:// refs in FLocat.

When calling de.lmu.cis.ocrd.cli.PostCorrectionCommand with an absolute path to the METS, it runs through, but produces output FLocats with absolute paths, which is (now) incorrect.

But when calling with just mets.xml inside the workspace directory, the postprocessor crashes:

22:32:03.614 DEBUG cis.PostCorrectionCommand - loading page
java.lang.NullPointerException
	at de.lmu.cis.ocrd.pagexml.METS$File.openLocalPath(METS.java:175)
	at de.lmu.cis.ocrd.pagexml.METS$File.openInputStream(METS.java:161)
	at de.lmu.cis.ocrd.pagexml.METSFileGroupReader.getPages(METSFileGroupReader.java:41)
	at de.lmu.cis.ocrd.pagexml.METSFileGroupReader.eachWord(METSFileGroupReader.java:54)
	at de.lmu.cis.ocrd.pagexml.METSFileGroupReader.getBaseOCRTokenReader(METSFileGroupReader.java:77)
	at de.lmu.cis.ocrd.pagexml.Workspace.getBaseOCRTokenReader(Workspace.java:33)
	at de.lmu.cis.ocrd.cli.ParametersCommand.getProfile(ParametersCommand.java:92)
	at de.lmu.cis.ocrd.cli.ParametersCommand.getProfile(ParametersCommand.java:61)
	at de.lmu.cis.ocrd.cli.PostCorrectionCommand.predictRankings(PostCorrectionCommand.java:96)
	at de.lmu.cis.ocrd.cli.PostCorrectionCommand.postCorrect(PostCorrectionCommand.java:61)
	at de.lmu.cis.ocrd.cli.PostCorrectionCommand.execute(PostCorrectionCommand.java:37)
	at de.lmu.cis.ocrd.cli.Main.run(Main.java:33)
	at de.lmu.cis.ocrd.cli.Main.main(Main.java:9)

The reason is simply that when opening input files via METS.File.openLocalPath, the first reference

ocrd-postcorrection/src/main/java/de/lmu/cis/ocrd/pagexml/METS.java

Line 175 in 49decc4

final Path relative = Paths.get(workspace.toString(), path.toString());

is null, because the file instance gets created in

ocrd-postcorrection/src/main/java/de/lmu/cis/ocrd/pagexml/METS.java

Line 69 in 49decc4

files.add(new METS.File(path.getParent(), f));

which expands to null for the parent of the relative path mets.xml.

So IMO the best fix would be to replace

ocrd-postcorrection/src/main/java/de/lmu/cis/ocrd/pagexml/METS.java

Line 102 in 49decc4

this.workspace = workspace;

with the current working directory if workspace is indeed empty.

[bertsky]

Oh, the original problem seems to be not about absolute paths but the missing @LOCTYPE="OTHER" and @OTHERLOCTYPE="FILE".