Alleviate problems on case-insensitive file systems

We have _no_ foolproof way to correctly compare paths:

* IPath treats paths always case-sensitively, both in equals()
  and in isPrefixOf(), which can give rise to unexpected problems
  on case-insensitive file systems such as NTFS on Windows or HFS+
  on OS X.
* java.io.File considers HFS+ (Mac) a case-sensitive UnixFileSystem,
  which is incorrect. (HFS+ can be either, and by default on Macs
  is case-insensitive.) On Windows, File is indeed case-insensitive.
* java.nio.file.Path also uses a case-sensitive sun.nio.fs.UnixPath
  on HFS+. On Windows, it is case-insensitive.
* org.eclipse.jgit.util.FS_POSIX.isCaseSensitive() returns
  unconditionally false for Macs. However, HFS+ partitions _can_ be
  case-sensitive. Furthermore, org.eclipse.jgit.util.FS doesn't have
  operations for case-normalization.
* org.eclipse.core.internal.resources.Project sets the project location
  to the canonicalized file path. File.getCanonicalFile() does appear
  to normalize capitalization to the form actually used in the file
  system.
* Many places in EGit do path comparisons between Eclipse IResources
  and git working trees using any of the possibilities above.
  
Options to fix this are:
* Use java.io.File or java.nio.file.Path, but that would leave HFS+ out
  in the cold. Would require lots of changes throughout EGit to root
  out any uses of comparisons via IPath.
* Write our own comparison and prefix methods. Make sure only those are
  used. Any collections storing paths or files would need to be checked
  and adapted; or maybe we'd even need or own subclass of File...
* Ensure that we use for repositories only the canonical path, like
  Eclipse core does for IProjects, so that the same casing is used.

This change implements the latter. It ensures that EGit and the
Eclipse resource tree both have the same idea of where things are and
should thus resolve most case-sensitivity problems, even if IPath is
used. (That's bug 477281.)

Fixes bug 478877. Depends on https://git.eclipse.org/r/#/c/58760/ in
JGit. 
  
Bug: 477281
Bug: 478877
Change-Id: I1d29203e678afb3fb43a6fcb334706c9473afc4e
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

0 files changed, 0 insertions, 0 deletions