import-dsc: Document new ff checks

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

diff --git a/dgit.1 b/dgit.1
index c2541f0eb8163a8c8ffafff0f288bf634c4628ff..2c583fe842b1b610d6cc6846b91208e76b01618a 100644 (file)
--- a/dgit.1
+++ b/dgit.1
@@ -240,7 +240,7 @@ other kinds of more exotic history.  If dgit can't find a suitable
 linearisation of your history, by default it will fail, but you can
 ask it to generate a single squashed patch instead.
 .TP
-.BI "dgit import-dsc " ../path/to/.dsc branch
+\fBdgit import-dsc\fR \fI../path/to/.dsc\fR [\fB+\fR|\fB..\fR]branch
 Import a Debian-format source package,
 specified by its .dsc,
 into git,
@@ -257,6 +257,25 @@ and it therefore does not
 make a pseudomerge to bind the import
 into any existing git history.
 
+If
+.I branch
+is prefixed with
+.B +
+then if it already exists, it will be simply ovewritten,
+no matter its existing contents.
+If
+.I branch
+is prefixed with
+.B ..
+then if it already exists
+and dgit actually imports the dsc
+(rather than simply reading the git commit out of the Dgit field),
+dgit will make a pseudomerge
+so that the result is necessarily fast forward
+from the existing branch.
+Otherwise, if branch already exists,
+dgit will stop with an error message.
+
 If
 .I branch
 does not start with refs/, refs/heads/ is prepended.