symbolic ref: refuse non-ref targets in HEAD

diff --git a/Documentation/git-commit.txt b/Documentation/git-commit.txt
index 5cce3a379167845a7c47e37d42e6b43ca399fa6c..b5d81be7ecd60daa1a1d476441ca58e6b732d9ef 100644 (file)
--- a/Documentation/git-commit.txt
+++ b/Documentation/git-commit.txt
@@ -29,7 +29,8 @@ The content to be added can be specified in several ways:
 
 3. by listing files as arguments to the 'commit' command, in which
    case the commit will ignore changes staged in the index, and instead
-   record the current content of the listed files;
+   record the current content of the listed files (which must already
+   be known to git);
 
 4. by using the -a switch with the 'commit' command to automatically
    "add" changes from all known files (i.e. all files that are already
@@ -75,8 +76,10 @@ OPTIONS
        read the message from the standard input.
 
 --author=<author>::
-       Override the author name used in the commit.  Use
-       `A U Thor <author@example.com>` format.
+       Override the author name used in the commit.  You can use the
+       standard `A U Thor <author@example.com>` format.  Otherwise,
+       an existing commit that matches the given string and its author
+       name is used.
 
 -m <msg>::
 --message=<msg>::
@@ -143,6 +146,10 @@ It is a rough equivalent for:
 ------
 but can be used to amend a merge commit.
 --
++
+You should understand the implications of rewriting history if you
+amend a commit that has already been published.  (See the "RECOVERING
+FROM UPSTREAM REBASE" section in linkgit:git-rebase[1].)
 
 -i::
 --include::