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https://issues.apache.org/jira/browse/VFS-753?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17031078#comment-17031078
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John Webb commented on VFS-753:
-------------------------------
[~ggregory]
I suspect the fix has the side effect of telling the class that execution is
enabled on the server when it isn't. detectExecDisabled relies on a throw to
return true however the fix simply catches and logs. I obviously don't know the
code as well as you but worry that a false negative from detectExecDisabled may
lead to undesirable behaviour.
> NumberFormatException in SftpFileSystem::getUId
> -----------------------------------------------
>
> Key: VFS-753
> URL: https://issues.apache.org/jira/browse/VFS-753
> Project: Commons VFS
> Issue Type: Bug
> Affects Versions: 2.5.0
> Reporter: John Webb
> Priority: Major
> Fix For: 2.6.1
>
>
> When calling FileSystemManager::resolveFile(...) connecting to a specific
> sftp server a NumberFormat exception is thrown and a FileObject is not
> returned.
> When the SftpFileSystem constructor is called there is a call to
> detectExecDisabled which in turn calls getUid. SftpFileSystem::getUId assumes
> that executeCommand(...) will always return non zero (the channel exit
> status) for execution failure.
> In the case of the sftp server that we are connecting to, the channel exit
> status remains zero however the returned buffer contains the string "This
> server does not provide shell access, only SFTP. Goodbye.". This causes a
> NumberFormatException in getUId.
> This behaviour does not occur in version 2.4.1
> Here is the relevent snippet from the stack trace:
> java.lang.NumberFormatException: For input string: "This server does not
> provide shell access, only SFTP. Goodbye."
> at
> java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
> at java.lang.Integer.parseInt(Integer.java:580)
> at java.lang.Integer.parseInt(Integer.java:615)
> at
> org.apache.commons.vfs2.provider.sftp.SftpFileSystem.getUId(SftpFileSystem.java:281)
> at
> org.apache.commons.vfs2.provider.sftp.SftpFileSystem.detectExecDisabled(SftpFileSystem.java:344)
> at
> org.apache.commons.vfs2.provider.sftp.SftpFileSystem.<init>(SftpFileSystem.java:94)
> at
> org.apache.commons.vfs2.provider.sftp.SftpFileProvider.doCreateFileSystem(SftpFileProvider.java:93)
> at
> org.apache.commons.vfs2.provider.AbstractOriginatingFileProvider.getFileSystem(AbstractOriginatingFileProvider.java:93)
> at
> org.apache.commons.vfs2.provider.AbstractOriginatingFileProvider.findFile(AbstractOriginatingFileProvider.java:72)
> at
> org.apache.commons.vfs2.provider.AbstractOriginatingFileProvider.findFile(AbstractOriginatingFileProvider.java:56)
> at
> org.apache.commons.vfs2.impl.DefaultFileSystemManager.resolveFile(DefaultFileSystemManager.java:717)
> at
> org.apache.commons.vfs2.impl.DefaultFileSystemManager.resolveFile(DefaultFileSystemManager.java:654)
> at
> com.shortcuts.lambda.google_reserve_sftp.util.SFTPUtil.ls(SFTPUtil.java:68)
> at
> com.shortcuts.lambda.google_reserve_sftp.util.SFTPUtilTest.testConnectToGoogle(SFTPUtilTest.java:48)
> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
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