When running
CYGWIN=winsymlinks:nativestrict ln -s .. abc
the counter-intuitive result is _not_ a symbolic link to `..`, but
instead to `../../$(basename "$PWD")`.
The reason for this is that the search for the longest common prefix
assumes that the link target is not a strict prefix of the parent
directory of the link itself.
Let's fix that.
Signed-off-by: Johannes Schindelin <[email protected]>
---
Published-As:
https://github.com/dscho/msys2-runtime/releases/tag/fix-dotdot-native_symlink-v1
Fetch-It-Via: git fetch https://github.com/dscho/msys2-runtime
fix-dotdot-native_symlink-v1
I investigated a failure in the Git test suite and was quite
surprised that `ln -s .. dir/link-git` resulted in this:
link-dir -> ../../trash\ directory.t1006-cat-file
instead of this:
link-dir -> ..
winsup/cygwin/path.cc | 21 ++++++++++++++++-----
1 file changed, 16 insertions(+), 5 deletions(-)
diff --git a/winsup/cygwin/path.cc b/winsup/cygwin/path.cc
index 42919a7cf5..ed08398930 100644
--- a/winsup/cygwin/path.cc
+++ b/winsup/cygwin/path.cc
@@ -1855,9 +1855,18 @@ symlink_native (const char *oldpath, path_conv
&win32_newpath)
while (towupper (*++c_old) == towupper (*++c_new))
;
/* The last component could share a common prefix, so make sure we end
- up on the first char after the last common backslash. */
- while (c_old[-1] != L'\\')
- --c_old, --c_new;
+ up on the first char after the last common backslash.
+
+ However, if c_old is a strict prefix of c_new (at a component
+ boundary), or vice versa, then do not try to find the last common
+ backslash. */
+ if ((!*c_old || *c_old == L'\\') && (!*c_new || *c_new == L'\\'))
+ c_old += !!*c_old, c_new += !!*c_new;
+ else
+ {
+ while (c_old[-1] != L'\\')
+ --c_old, --c_new;
+ }
/* 2. Check if prefix is long enough. The prefix must at least points to
a complete device: \\?\X:\ or \\?\UNC\server\share\ are the
minimum
@@ -1882,8 +1891,10 @@ symlink_native (const char *oldpath, path_conv
&win32_newpath)
final_oldpath = &final_oldpath_buf;
final_oldpath->Buffer = tp.w_get ();
PWCHAR e_old = final_oldpath->Buffer;
- while (num-- > 0)
- e_old = wcpcpy (e_old, L"..\\");
+ while (num > 1 || (num == 1 && *c_old))
+ e_old = wcpcpy (e_old, L"..\\"), num--;
+ if (num > 0)
+ e_old = wcpcpy (e_old, L"..");
wcpcpy (e_old, c_old);
}
}
base-commit: 1186791e9f404644832023b8fa801227c2995ab7
--
2.50.0.rc2.windows.1
