feat: add resolve cmd

Commands.md

@@ -58,6 +58,7 @@
  - [`git rename-remote`](#git-rename-remote)
  - [`git repl`](#git-repl)
  - [`git reset-file`](#git-reset-file)
+ - [`git resolve`](#git-resolve)
  - [`git root`](#git-root)
  - [`git rscp`](#git-scp)
  - [`git scp`](#git-scp)
@@ -1402,6 +1403,16 @@ or reset one file to certain commit
 $ git reset-file .htaccess dc82b19
 ```
 
+## git resolve
+
+On default text-editor, open unmerged ("both modified" `status`) files in working-directory that have errors (e.g. conflict-markers),
+then auto-stage all (in full work-tree) unmerged files without errors,
+and finally [`continue`](#git-continue) (if possible).
+
+```bash
+$ git resolve
+```
+
 ## git mr
 
 Checks out a merge request from GitLab. Usage: `git mr <ID|URL> [REMOTE]`.

bin/git-resolve

@@ -0,0 +1,31 @@
+#!/usr/bin/env bash
+set -eufo pipefail
+IFS=$' \t'
+
+#shellcheck disable=SC2046
+# ignore files outside WD, to avoid overload
+git diff --name-only --diff-filter=U --relative -z |
+    while IFS= read -r -d '' f; do
+        # `--quiet` implies `--exit-code` which is incompatible with `--check`;
+        # however, it could be special-cased internally, so it could work
+        # (untested)
+        if ! git diff --check -- "$f" &>/dev/null; then
+            printf '%s\0' "$f"
+        fi
+    done |
+    # WARN: `-r` is too new
+    # https://github.com/tj/git-extras/pull/1233#issuecomment-3957233996
+    xargs -0r $(git var GIT_EDITOR)
+
+# user might have removed other conflict-markers,
+# so check full WT
+git diff --name-only --diff-filter=U -z |
+    while IFS= read -r -d '' f; do
+        # WARN: `f` is relative to repo root!
+        # this might be broken
+        if git diff --check -- "$f"; then
+            git add -- "$f"
+        fi
+    done
+
+git continue