Warn (and ask confirmation) on prefix sharing across subtrees. Closes …

…#17.

git-stree

@@ -38,6 +38,7 @@ CYAN=36
 GRAY=37
 GREEN=32
 RED=31
+YELLOW=33
 
 # Grabbing CLI arguments and the main subcommand
 args=("$@")
@@ -68,6 +69,8 @@ function add_subtree
  error false "A remote already exists for '$name' ($remote_name). Subtree already defined?"
  fi
 
+ check_conflicting_strees "$prefix"
+
  ensure_attached_head
  ensure_no_stage
 
@@ -77,10 +80,14 @@ function add_subtree
  git config --local "stree.$root_key.branch" "$branch" &&
  git read-tree --prefix="$prefix" -u "$remote_name/$branch" &&
  git commit -m "[STree] Added stree '$root_key' in $prefix" &&
- git config --local "stree.$root_key.latest-sync" "$(git rev-parse --short HEAD)"
-
- echo ''
- yay "STree '$root_key' configured, 1st injection committed."
+ git config --local "stree.$root_key.latest-sync" "$(git rev-parse --short HEAD)" &&
+ echo '' &&
+ yay "STree '$root_key' configured, 1st injection committed." ||
+
+ echo '' &&
+ git remote rm "$remote_name" &&
+ git config --local --remove-section "stree.$root_key" &&
+ error false "STree '$root_key' could not be configured."
 }
 
 # Helper: determines whether a branch exists
@@ -89,6 +96,40 @@ function branch_exists
  [ "refs/heads/$1" == "$(git rev-parse --symbolic-full-name --verify --quiet "$1")" ]
 }
 
+# Helper: maintains detected stree conflict state in a file, to work across subshell boundaries.
+function has_conflicts
+{
+ local sentinel="$(git rev-parse --git-dir)/STREE_CONFLICTS"
+ case "$1" in
+ yes) echo 'yes' > "$sentinel";;
+ reset) rm -f "$sentinel" && false;;
+ *) [ -f "$sentinel" ] && [ "yes" = "$(cat "$sentinel")" ];;
+ esac
+}
+
+# Helper: checks that the passed path doesn't conflict with existing stree
+# definitions. If it does, lists them, and asks for confirmation. Refusal
+# stops the script.
+function check_conflicting_strees()
+{
+ local path="$1"
+ local list=$(get_subtree_list)
+ has_conflicts reset
+
+ echo "$list" | while read stree remoting prefix; do
+ [ "$prefix" != "$path" ] && continue
+
+ has_conflicts || message $YELLOW "Existing strees use that prefix already:"
+ message $YELLOW " • $stree ($remoting)"
+ has_conflicts yes
+ done
+
+ has_conflicts || return
+ has_conflicts reset
+
+ confirm N "Do you want to proceed and setup another stree with that same prefix?"
+}
+
 # Command: `git stree clear`
 function clear_subtrees
 {
@@ -112,6 +153,29 @@ want:
  yay 'Successfully cleared all subtree definitions.'
 }
 
+# Helper: confirms with a Y/N question and repeat until a proper answer is given.
+# Arguments: color, default (Y or N), message
+function confirm
+{
+ local question="Yn"
+ local reply="$1"
+
+ [ "N" = "$reply" ] && question="yN"
+
+ while true; do
+ $is_tty && echo -en "\033[0;${CYAN}m"
+ read -r -n 1 -p "$2 [$question] " reply
+ $is_tty && echo -en "\033[0m"
+
+ reply=$(echo "$reply" | tr a-z A-Z)
+ [ -z "$reply" ] && reply="$1"
+ [ "Y" = "$reply" -o "N" = "$reply" ] && break
+ echo ''
+ done
+
+ [ "N" = "$reply" ] && exit 42
+}
+
 # Helper: discreet info message. This will show up in gray on STDOUT.
 function discreet
 {