git-svn: Expand documentation for --follow-parent

Describe what the option --follow-parent does, and what happens if it is
set or unset.

Signed-off-by: Sebastian Leske <sebastian.leske@sleske.name>
Acked-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-svn.txt b/Documentation/git-svn.txt
index 0f5d9f92d3224ce9e39c42d968a7ed0b5a7c41d7..84bff9b447eb0ab25f987d592af61d7634594a4d 100644 (file)
--- a/Documentation/git-svn.txt
+++ b/Documentation/git-svn.txt
@@ -621,10 +621,19 @@ ADVANCED OPTIONS
        Default: "svn"
 
 --follow-parent::
+       This option is only relevant if we are tracking branches (using
+       one of the repository layout options --trunk, --tags,
+       --branches, --stdlayout). For each tracked branch, try to find
+       out where its revision was copied from, and set
+       a suitable parent in the first git commit for the branch.
        This is especially helpful when we're tracking a directory
-       that has been moved around within the repository, or if we
-       started tracking a branch and never tracked the trunk it was
-       descended from. This feature is enabled by default, use
+       that has been moved around within the repository.  If this
+       feature is disabled, the branches created by 'git svn' will all
+       be linear and not share any history, meaning that there will be
+       no information on where branches were branched off or merged.
+       However, following long/convoluted histories can take a long
+       time, so disabling this feature may speed up the cloning
+       process. This feature is enabled by default, use
        --no-follow-parent to disable it.
 +
 [verse]