Merge branch 'jc/name-rev-stdin'

"git name-rev --stdin" does not behave like usual "--stdin" at
all.  Start the process of renaming it to "--annotate-stdin".

* jc/name-rev-stdin:
  name-rev.c: use strbuf_getline instead of limited size buffer
  name-rev: deprecate --stdin in favor of --annotate-stdin

Documentation/git-name-rev.txt

@@ -42,11 +42,37 @@ OPTIONS
 --all::
 	List all commits reachable from all refs
 
---stdin::
+--annotate-stdin::
 	Transform stdin by substituting all the 40-character SHA-1
 	hexes (say $hex) with "$hex ($rev_name)".  When used with
 	--name-only, substitute with "$rev_name", omitting $hex
-	altogether.  Intended for the scripter's use.
+	altogether.
++
+For example:
++
+-----------
+$ cat sample.txt
+
+An abbreviated revision 2ae0a9cb82 will not be substituted.
+The full name after substitution is 2ae0a9cb8298185a94e5998086f380a355dd8907,
+while its tree object is 70d105cc79e63b81cfdcb08a15297c23e60b07ad
+
+$ git name-rev --annotate-stdin <sample.txt
+
+An abbreviated revision 2ae0a9cb82 will not be substituted.
+The full name after substitution is 2ae0a9cb8298185a94e5998086f380a355dd8907 (master),
+while its tree object is 70d105cc79e63b81cfdcb08a15297c23e60b07ad
+
+$ git name-rev --name-only --annotate-stdin <sample.txt
+
+An abbreviated revision 2ae0a9cb82 will not be substituted.
+The full name after substitution is master,
+while its tree object is 70d105cc79e63b81cfdcb08a15297c23e60b07ad
+-----------
+
+--stdin::
+	This option is deprecated in favor of 'git name-rev --annotate-stdin'.
+	They are functionally equivalent.
 
 --name-only::
 	Instead of printing both the SHA-1 and the name, print only