gcp: interactively select target branch

When we want to perform a cherry pick, we had to pass the target branch
as an argument to gcp. Forgit, however, aims to make git selections
interactive where possible. Hence it seems natural to select the target
branch interactively as well.

conf.d/forgit.plugin.fish

@@ -374,9 +374,43 @@ function forgit::cherry::pick -d "git cherry-picking" --argument-names 'target'
         -m -0 --tiebreak=index
         $FORGIT_CHERRY_PICK_FZF_OPTS
     "
-    git cherry "$base" "$target" --abbrev -v | forgit::reverse_lines |
-        env FZF_DEFAULT_OPTS="$opts" fzf | cut -d' ' -f2 | forgit::reverse_lines |
-        xargs -I% git cherry-pick %
+    set fzf_selection (git cherry "$base" "$target" --abbrev -v | forgit::reverse_lines |
+        env FZF_DEFAULT_OPTS="$opts" fzf)
+
+    set fzf_exitval $status
+    test $fzf_exitval != 0 && return $fzf_exitval
+    set commits (echo "$fzf_selection" | forgit::reverse_lines | cut -d' ' -f2)
+
+    git cherry-pick $commits
+
+end
+
+function forgit::cherry::pick::from::branch -d "git cherry-picking with interactive branch selection"
+    forgit::inside_work_tree || return 1
+
+    set preview "git log {1} $forgit_log_preview_options"
+
+    set opts "
+        $FORGIT_FZF_DEFAULT_OPTS
+        +s +m --tiebreak=index --header-lines=1
+        --preview=\"$preview\"
+        $FORGIT_CHERRY_PICK_FROM_BRANCH_FZF_OPTS
+        "
+
+    set cmd "git branch --color=always --all | LC_ALL=C sort -k1.1,1.1 -rs"
+
+    # loop until either the branch selector is closed or a commit to be cherry
+    # picked has been selected from within a branch
+    while true
+
+        set branch (eval "$cmd" | FZF_DEFAULT_OPTS="$opts" fzf | awk '{print $1}')
+        test -z "$branch" && return 1
+
+        forgit::cherry::pick "$branch"
+
+        set exitval $status
+        test $exitval != 130 && return $exitval
+    end
 end
 
 function forgit::fixup -d "git fixup"
@@ -640,9 +674,9 @@ if test -z "$FORGIT_NO_ALIASES"
     end
 
     if test -n "$forgit_cherry_pick"
-        alias $forgit_cherry_pick 'forgit::cherry::pick'
+        alias $forgit_cherry_pick 'forgit::cherry::pick::from::branch'
     else
-        alias gcp 'forgit::cherry::pick'
+        alias gcp 'forgit::cherry::pick::from::branch'
     end
 
     if test -n "$forgit_rebase"

forgit.plugin.zsh

@@ -169,7 +169,7 @@ forgit::clean() {
 }
 
 forgit::cherry::pick() {
-    local base target preview opts
+    local base target preview opts fzf_selection fzf_exitval
     base=$(git branch --show-current)
     [[ -z $1 ]] && echo "Please specify target branch" && return 1
     target="$1"
@@ -180,9 +180,44 @@ forgit::cherry::pick() {
         -m -0 --tiebreak=index
         $FORGIT_CHERRY_PICK_FZF_OPTS
     "
-    git cherry "$base" "$target" --abbrev -v | forgit::reverse_lines |
-        FZF_DEFAULT_OPTS="$opts" fzf | cut -d' ' -f2 | forgit::reverse_lines |
-        xargs -I% git cherry-pick %
+    fzf_selection=$(git cherry "$base" "$target" --abbrev -v | forgit::reverse_lines |
+        FZF_DEFAULT_OPTS="$opts" fzf)
+    fzf_exitval=$?
+    [[ $fzf_exitval != 0 ]] && return $fzf_exitval
+
+    commits=()
+    while IFS="" read -r line
+    do
+        commits+=("$line")
+    done < <(echo "$fzf_selection" | forgit::reverse_lines | cut -d' ' -f2)
+
+    git cherry-pick "${commits[@]}"
+}
+
+forgit::cherry::pick::from::branch() {
+    forgit::inside_work_tree || return 1
+    [[ $# -ne 0 ]] && { git checkout -b "$@"; return $?; }
+    local cmd preview opts branch exitval
+    cmd="git branch --color=always --all | LC_ALL=C sort -k1.1,1.1 -rs"
+    preview="git log {1} $forgit_log_preview_options"
+    opts="
+        $FORGIT_FZF_DEFAULT_OPTS
+        +s +m --tiebreak=index --header-lines=1
+        --preview=\"$preview\"
+        $FORGIT_CHERRY_PICK_FROM_BRANCH_FZF_OPTS
+        "
+    # loop until either the branch selector is closed or a commit to be cherry
+    # picked has been selected from within a branch
+    while true
+    do
+        branch="$(eval "$cmd" | FZF_DEFAULT_OPTS="$opts" fzf | awk '{print $1}')"
+        [[ -z "$branch" ]] && return 1
+
+        forgit::cherry::pick "$branch"
+
+        exitval=$?
+        [[ $exitval != 130 ]] && return $exitval
+    done
 }
 
 forgit::rebase() {
@@ -458,7 +493,7 @@ if [[ -z "$FORGIT_NO_ALIASES" ]]; then
     alias "${forgit_checkout_tag:-gct}"='forgit::checkout::tag'
     alias "${forgit_clean:-gclean}"='forgit::clean'
     alias "${forgit_stash_show:-gss}"='forgit::stash::show'
-    alias "${forgit_cherry_pick:-gcp}"='forgit::cherry::pick'
+    alias "${forgit_cherry_pick:-gcp}"='forgit::cherry::pick::from::branch'
     alias "${forgit_rebase:-grb}"='forgit::rebase'
     alias "${forgit_fixup:-gfu}"='forgit::fixup'
     alias "${forgit_blame:-gbl}"='forgit::blame'