diff --git a/lib/branch_create.tcl b/lib/branch_create.tcl
index 7f82424eda..0272d6f024 100644
--- a/lib/branch_create.tcl
+++ b/lib/branch_create.tcl
@@ -10,7 +10,9 @@ field w_name         ; # new branch name widget
 field name         {}; # name of the branch the user has chosen
 field name_type  user; # type of branch name to use
 
+field opt_merge    ff; # type of merge to apply to existing branch
 field opt_checkout  1; # automatically checkout the new branch?
+field reset_ok      0; # did the user agree to reset?
 
 constructor dialog {} {
 	global repo_config
@@ -63,12 +65,33 @@ constructor dialog {} {
 	set w_rev [::choose_rev::new $w.rev {Starting Revision}]
 	pack $w.rev -anchor nw -fill x -pady 5 -padx 5
 
-	labelframe $w.postActions -text {Post Creation Actions}
-	checkbutton $w.postActions.checkout \
-		-text {Checkout after creation} \
+	labelframe $w.options -text {Options}
+
+	frame $w.options.merge
+	label $w.options.merge.l -text {Update Existing Branch:}
+	pack $w.options.merge.l -side left
+	radiobutton $w.options.merge.no \
+		-text No \
+		-value no \
+		-variable @opt_merge
+	pack $w.options.merge.no -side left
+	radiobutton $w.options.merge.ff \
+		-text {Fast Forward Only} \
+		-value ff \
+		-variable @opt_merge
+	pack $w.options.merge.ff -side left
+	radiobutton $w.options.merge.reset \
+		-text {Reset} \
+		-value reset \
+		-variable @opt_merge
+	pack $w.options.merge.reset -side left
+	pack $w.options.merge -anchor nw
+
+	checkbutton $w.options.checkout \
+		-text {Checkout After Creation} \
 		-variable @opt_checkout
-	pack $w.postActions.checkout -anchor nw
-	pack $w.postActions -anchor nw -fill x -pady 5 -padx 5
+	pack $w.options.checkout -anchor nw
+	pack $w.options -anchor nw -fill x -pady 5 -padx 5
 
 	set name $repo_config(gui.newbranchtemplate)
 
@@ -84,7 +107,7 @@ constructor dialog {} {
 
 method _create {} {
 	global null_sha1 repo_config
-	global all_heads
+	global all_heads current_branch
 
 	switch -- $name_type {
 	user {
@@ -124,7 +147,46 @@ method _create {} {
 		focus $w_name
 		return
 	}
-	if {![catch {git show-ref --verify -- "refs/heads/$newbranch"}]} {
+
+	if {$newbranch eq $current_branch} {
+		tk_messageBox \
+			-icon error \
+			-type ok \
+			-title [wm title $w] \
+			-parent $w \
+			-message "'$newbranch' already exists and is the current branch."
+		focus $w_name
+		return
+	}
+
+	if {[catch {git check-ref-format "heads/$newbranch"}]} {
+		tk_messageBox \
+			-icon error \
+			-type ok \
+			-title [wm title $w] \
+			-parent $w \
+			-message "'$newbranch' is not an acceptable branch name."
+		focus $w_name
+		return
+	}
+
+	if {[catch {set new [$w_rev get_commit]}]} {
+		tk_messageBox \
+			-icon error \
+			-type ok \
+			-title [wm title $w] \
+			-parent $w \
+			-message "Invalid revision: [$w_rev get]"
+		return
+	}
+
+	set ref refs/heads/$newbranch
+	if {[catch {set cur [git rev-parse --verify "$ref^0"]}]} {
+		# Assume it does not exist, and that is what the error was.
+		#
+		set reflog_msg "branch: Created from [$w_rev get]"
+		set cur $null_sha1
+	} elseif {$opt_merge eq {no}} {
 		tk_messageBox \
 			-icon error \
 			-type ok \
@@ -133,52 +195,166 @@ method _create {} {
 			-message "Branch '$newbranch' already exists."
 		focus $w_name
 		return
-	}
-	if {[catch {git check-ref-format "heads/$newbranch"}]} {
-		tk_messageBox \
-			-icon error \
-			-type ok \
-			-title [wm title $w] \
-			-parent $w \
-			-message "We do not like '$newbranch' as a branch name."
-		focus $w_name
-		return
+	} else {
+		set mrb {}
+		catch {set mrb [git merge-base $new $cur]}
+		switch -- $opt_merge {
+		ff {
+			if {$mrb eq $new} {
+				# The current branch is actually newer.
+				#
+				set new $cur
+			} elseif {$mrb eq $cur} {
+				# The current branch is older.
+				#
+				set reflog_msg "merge [$w_rev get]: Fast-forward"
+			} else {
+				tk_messageBox \
+					-icon error \
+					-type ok \
+					-title [wm title $w] \
+					-parent $w \
+					-message "Branch '$newbranch' already exists.\n\nIt cannot fast-forward to [$w_rev get].\nA merge is required."
+				focus $w_name
+				return
+			}
+		}
+		reset {
+			if {$mrb eq $cur} {
+				# The current branch is older.
+				#
+				set reflog_msg "merge [$w_rev get]: Fast-forward"
+			} else {
+				# The current branch will lose things.
+				#
+				if {[_confirm_reset $this $newbranch $cur $new]} {
+					set reflog_msg "reset [$w_rev get]"
+				} else {
+					return
+				}
+			}
+		}
+		default {
+			tk_messageBox \
+				-icon error \
+				-type ok \
+				-title [wm title $w] \
+				-parent $w \
+				-message "Branch '$newbranch' already exists."
+			focus $w_name
+			return
+		}
+		}
 	}
 
-	if {[catch {set cmt [$w_rev get_commit]}]} {
-		tk_messageBox \
-			-icon error \
-			-type ok \
-			-title [wm title $w] \
-			-parent $w \
-			-message "Invalid starting revision: [$w_rev get]"
-		return
-	}
-	if {[catch {
-			git update-ref \
-				-m "branch: Created from [$w_rev get]" \
-				"refs/heads/$newbranch" \
-				$cmt \
-				$null_sha1
-		} err]} {
-		tk_messageBox \
-			-icon error \
-			-type ok \
-			-title [wm title $w] \
-			-parent $w \
-			-message "Failed to create '$newbranch'.\n\n$err"
-		return
+	if {$new ne $cur} {
+		if {[catch {
+				git update-ref -m $reflog_msg $ref $new $cur
+			} err]} {
+			tk_messageBox \
+				-icon error \
+				-type ok \
+				-title [wm title $w] \
+				-parent $w \
+				-message "Failed to create '$newbranch'.\n\n$err"
+			return
+		}
+	}
+
+	if {$cur eq $null_sha1} {
+		lappend all_heads $newbranch
+		set all_heads [lsort -uniq $all_heads]
+		populate_branch_menu
 	}
 
-	lappend all_heads $newbranch
-	set all_heads [lsort $all_heads]
-	populate_branch_menu
 	destroy $w
 	if {$opt_checkout} {
 		switch_branch $newbranch
 	}
 }
 
+method _confirm_reset {newbranch cur new} {
+	set reset_ok 0
+	set gitk [list do_gitk [list $cur ^$new]]
+
+	set c $w.confirm_reset
+	toplevel $c
+	wm title $c "Confirm Branch Reset"
+	wm geometry $c "+[winfo rootx $w]+[winfo rooty $w]"
+
+	pack [label $c.msg1 \
+		-anchor w \
+		-justify left \
+		-text "Resetting '$newbranch' to [$w_rev get] will lose the following commits:" \
+		] -anchor w
+
+	set list $c.list.l
+	frame $c.list
+	text $list \
+		-font font_diff \
+		-width 80 \
+		-height 10 \
+		-wrap none \
+		-xscrollcommand [list $c.list.sbx set] \
+		-yscrollcommand [list $c.list.sby set]
+	scrollbar $c.list.sbx -orient h -command [list $list xview]
+	scrollbar $c.list.sby -orient v -command [list $list yview]
+	pack $c.list.sbx -fill x -side bottom
+	pack $c.list.sby -fill y -side right
+	pack $list -fill both -expand 1
+	pack $c.list -fill both -expand 1 -padx 5 -pady 5
+
+	pack [label $c.msg2 \
+		-anchor w \
+		-justify left \
+		-text "Recovering lost commits may not be easy." \
+		]
+	pack [label $c.msg3 \
+		-anchor w \
+		-justify left \
+		-text "Reset '$newbranch'?" \
+		]
+
+	frame $c.buttons
+	button $c.buttons.visualize \
+		-text Visualize \
+		-command $gitk
+	pack $c.buttons.visualize -side left
+	button $c.buttons.reset \
+		-text Reset \
+		-command "
+			set @reset_ok 1
+			destroy $c
+		"
+	pack $c.buttons.reset -side right
+	button $c.buttons.cancel \
+		-default active \
+		-text Cancel \
+		-command [list destroy $c]
+	pack $c.buttons.cancel -side right -padx 5
+	pack $c.buttons -side bottom -fill x -pady 10 -padx 10
+
+	set fd [open "| git rev-list --pretty=oneline $cur ^$new" r]
+	while {[gets $fd line] > 0} {
+		set abbr [string range $line 0 7]
+		set subj [string range $line 41 end]
+		$list insert end "$abbr  $subj\n"
+	}
+	close $fd
+	$list configure -state disabled
+
+	bind $c    <Key-v> $gitk
+
+	bind $c <Visibility> "
+		grab $c
+		focus $c.buttons.cancel
+	"
+	bind $c <Key-Return> [list destroy $c]
+	bind $c <Key-Escape> [list destroy $c]
+	tkwait window $c
+	return $reset_ok
+}
+
 method _validate {d S} {
 	if {$d == 1} {
 		if {[regexp {[~^:?*\[\0- ]} $S]} {