t0001: fix on case-insensitive filesystems

On a case-insensitive filesystem, such as HFS+ or NTFS, it is possible
that the idea Bash has of the current directory differs in case from
what Git thinks it is. That's totally okay, though, and we should not
expect otherwise.

On Windows, for example, when you call

	cd C:\GIT-SDK-64

in a PowerShell and there exists a directory called `C:\git-sdk-64`, the
current directory will be reported in all upper-case. Even in a Bash
that you might call from that PowerShell. Git, however, will have
normalized this via `GetFinalPathByHandle()`, and the expectation in
t0001 that the recorded gitdir will match what `pwd` says will be
violated.

Let's address this by comparing these paths in a case-insensitive
manner when `core.ignoreCase` is `true`.

Reported by Jameson Miller.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/test-lib-functions.sh

@@ -888,6 +888,21 @@ test_cmp_rev () {
 	fi
 }
 
+# Compare paths respecting core.ignoreCase
+test_cmp_fspath () {
+	if test "x$1" = "x$2"
+	then
+		return 0
+	fi
+
+	if test true != "$(git config --get --type=bool core.ignorecase)"
+	then
+		return 1
+	fi
+
+	test "x$(echo "$1" | tr A-Z a-z)" =  "x$(echo "$2" | tr A-Z a-z)"
+}
+
 # Print a sequence of integers in increasing order, either with
 # two arguments (start and end):
 #