darcs-fast-import: better error handling for symlinks

The importer can't handle them till Darcs does not so, but at least we
can give an easy-to-understand error message and a separate exit code.

3 files changed, 42 insertions, 0 deletions

diff --git a/exporters/darcs/darcs-fast-import b/exporters/darcs/darcs-fast-import
index 4892438..a7a4834 100755
--- a/exporters/darcs/darcs-fast-import
+++ b/exporters/darcs/darcs-fast-import
@@ -198,6 +198,9 @@ class Handler:
 				os.system("darcs add %s" % dest)
 			elif self.line.startswith("M "):
 				items = self.line.split(' ')
+				if items[1] == "120000":
+					print "Adding symbolic links (symlinks) is not supported by Darcs."
+					sys.exit(2)
 				path = items[3][:-1]
 				dir = os.path.split(path)[0]
 				if len(dir) and not os.path.exists(dir):
diff --git a/exporters/darcs/darcs-fast-import.txt b/exporters/darcs/darcs-fast-import.txt
index 09c7b1e..314b947 100644
--- a/exporters/darcs/darcs-fast-import.txt
+++ b/exporters/darcs/darcs-fast-import.txt
@@ -33,3 +33,11 @@ as well, via the --import-marks / --export-marks switches.
 --logfile::
 	The output of external commands are redirected to a log file. You can
 	specify the path of that file with this parameter.
+
+== EXIT CODES
+
+The exit code is:
+
+* 0 on success
+* 1 on unhandled exception
+* 2 in case the stream would try to let the importer create a symlink
diff --git a/exporters/darcs/t/testimport-gitsymlink.sh b/exporters/darcs/t/testimport-gitsymlink.sh
new file mode 100644
index 0000000..340a493
--- /dev/null
+++ b/exporters/darcs/t/testimport-gitsymlink.sh
@@ -0,0 +1,31 @@
+. ./lib.sh
+
+create_git test
+cd test
+# add two dirs with the some contents, then remove the second
+# and make it a symlink to the first
+mkdir dira
+echo blabla > dira/file
+echo blablabla > dira/file2
+mkdir dirb
+touch dirb/file
+touch dirb/file2
+git add dira dirb
+git commit -a -m "add dira/dirb"
+rm -rf dirb
+ln -s dira dirb
+git add dirb
+git commit -a -m "change a dir to a symlink"
+cd ..
+
+rm -rf test.darcs
+mkdir test.darcs
+cd test.darcs
+darcs init
+cd ..
+(cd test; git fast-export --progress=2 HEAD) | (cd test.darcs; darcs-fast-import)
+# we *do* want this to fail, but with error code 2. that means that we
+# detected that symlinks are not supported and the user does not get a
+# meaningless exception
+[ $? = 2 ]
+exit $?