Merge branch 'fc/send-email-annotate'

Allows format-patch --cover-letter to be configurable; the most
notable is the "auto" mode to create cover-letter only for multi
patch series.

* fc/send-email-annotate:
  rebase-am: explicitly disable cover-letter
  format-patch: trivial cleanups
  format-patch: add format.coverLetter configuration variable
  log: update to OPT_BOOL
  format-patch: refactor branch name calculation
  format-patch: improve head calculation for cover-letter
  send-email: make annotate configurable

Documentation/config.txt

@@ -1109,6 +1109,11 @@ format.signoff::
     the rights to submit this work under the same open source license.
     Please see the 'SubmittingPatches' document for further discussion.
 
+format.coverLetter::
+	A boolean that controls whether to generate a cover-letter when
+	format-patch is invoked, but in addition can be set to "auto", to
+	generate a cover-letter only when there's more than one patch.
+
 filter.<driver>.clean::
 	The command which is used to convert the content of a worktree
 	file to a blob upon checkin.  See linkgit:gitattributes[5] for
@@ -2016,6 +2021,7 @@ sendemail.<identity>.*::
 
 sendemail.aliasesfile::
 sendemail.aliasfiletype::
+sendemail.annotate::
 sendemail.bcc::
 sendemail.cc::
 sendemail.cccmd::

Documentation/git-format-patch.txt

@@ -20,7 +20,7 @@ SYNOPSIS
 		   [--ignore-if-in-upstream]
 		   [--subject-prefix=Subject-Prefix] [(--reroll-count|-v) <n>]
 		   [--to=<email>] [--cc=<email>]
-		   [--cover-letter] [--quiet] [--notes[=<ref>]]
+		   [--[no-]cover-letter] [--quiet] [--notes[=<ref>]]
 		   [<common diff options>]
 		   [ <since> | <revision range> ]
 
@@ -195,7 +195,7 @@ will want to ensure that threading is disabled for `git send-email`.
 	`Cc:`, and custom) headers added so far from config or command
 	line.
 
---cover-letter::
+--[no-]cover-letter::
 	In addition to the patches, generate a cover letter file
 	containing the shortlog and the overall diffstat.  You can
 	fill in a description in the file before sending it out.
@@ -260,6 +260,7 @@ attachments, and sign off patches with configuration variables.
 	cc = <email>
 	attach [ = mime-boundary-string ]
 	signoff = true
+	coverletter = auto
 ------------
 
 

Documentation/git-send-email.txt

@@ -45,8 +45,9 @@ Composing
 ~~~~~~~~~
 
 --annotate::
-	Review and edit each patch you're about to send. See the
-	CONFIGURATION section for 'sendemail.multiedit'.
+	Review and edit each patch you're about to send. Default is the value
+	of 'sendemail.annotate'. See the CONFIGURATION section for
+	'sendemail.multiedit'.
 
 --bcc=<address>::
 	Specify a "Bcc:" value for each email. Default is the value of