Merge branch 'jk/format-patch-from'

"git format-patch" learned "--from[=whom]" option, which sets the
"From: " header to the specified person (or the person who runs the
command, if "=whom" part is missing) and move the original author
information to an in-body From: header as necessary.

* jk/format-patch-from:
  teach format-patch to place other authors into in-body "From"
  pretty.c: drop const-ness from pretty_print_context

diff --cc commit.h
Simple merge

diff --cc log-tree.c
index 60f32a3965feeba30bd7ba7ba724c5d7dfd52be8,67da27f909067132c79fdc028679895e280b7ab1..a49d8e895d3ad24f00e8504ec3eccfbddead6b4c
--- 1/log-tree.c
--- 2/log-tree.c
+++ b/log-tree.c
@@@ -617,7 -617,8 +617,9 @@@ void show_log(struct rev_info *opt
        ctx.fmt = opt->commit_format;
        ctx.mailmap = opt->mailmap;
        ctx.color = opt->diffopt.use_color;
 +      ctx.output_encoding = get_log_output_encoding();
+       if (opt->from_ident.mail_begin && opt->from_ident.name_begin)
+               ctx.from_ident = &opt->from_ident;
        pretty_print_commit(&ctx, commit, &msgbuf);
  
        if (opt->add_signoff)