vim-patch: handle tags, pass through git-log options (#10140)

* scripts/vim-patch.sh: fall back to "origin" for remote

Without this, it would fail e.g. with a locally cloned repo of Neovim.

* scripts/vim-patch.sh: assign_commit_details: handle tags  [ci skip]

- Handle "v" prefix from Vim tags.
- Exit in case of error therein already.

* -l/-L: pass through git-log options  [ci skip]

This allows for only listing missing patches for a given Vim file:

> scripts/vim-patch.sh -L src/edit.c

scripts/vim-patch.sh

@@ -21,8 +21,8 @@ usage() {
   echo
   echo "Options:"
   echo "    -h                 Show this message and exit."
-  echo "    -l                 List missing Vim patches."
-  echo "    -L                 List missing Vim patches (for scripts)."
+  echo "    -l [git-log opts]  List missing Vim patches."
+  echo "    -L [git-log opts]  List missing Vim patches (for scripts)."
   echo "    -M                 List all merged patch-numbers (at current v:version)."
   echo "    -p {vim-revision}  Download and generate a Vim patch. vim-revision"
   echo "                       can be a Vim version (8.0.xxx) or a Git hash."
@@ -34,6 +34,11 @@ usage() {
   echo
   echo "    \$VIM_SOURCE_DIR controls where Vim sources are found"
   echo "    (default: '${VIM_SOURCE_DIR_DEFAULT}')"
+  echo
+  echo "Examples:"
+  echo
+  echo " - List missing patches for a given file (in the Vim source):"
+  echo "   $0 -l -- src/edit.c"
 }
 
 msg_ok() {
@@ -110,30 +115,44 @@ commit_message() {
 }
 
 find_git_remote() {
-  git remote -v \
-    | awk '$2 ~ /github.com[:\/]neovim\/neovim/ && $3 == "(fetch)" {print $1; exit}'
+  git_remote=$(git remote -v \
+    | awk '$2 ~ /github.com[:\/]neovim\/neovim/ && $3 == "(fetch)" {print $1; exit}')
+  if [[ -z "$git_remote" ]]; then
+    git_remote="origin"
+  fi
+  echo "$git_remote"
 }
 
+# Assign variables for a given Vim tag, patch version, or commit.
+# Might exit in case it cannot be found.
 assign_commit_details() {
-  if [[ ${1} =~ [0-9]\.[0-9]\.[0-9]{3,4} ]]; then
+  local vim_commit_ref
+  if [[ ${1} =~ v?[0-9]\.[0-9]\.[0-9]{3,4} ]]; then
     # Interpret parameter as version number (tag).
-    vim_version="${1}"
-    vim_tag="v${1}"
-    vim_commit=$(cd "${VIM_SOURCE_DIR}" \
-      && git log -1 --format="%H" "${vim_tag}")
+    if [[ "${1:0:1}" == v ]]; then
+      vim_version="${1:1}"
+      vim_tag="${1}"
+    else
+      vim_version="${1}"
+      vim_tag="v${1}"
+    fi
+    vim_commit_ref="$vim_tag"
     local munge_commit_line=true
   else
     # Interpret parameter as commit hash.
     vim_version="${1:0:12}"
     vim_tag=
-    vim_commit=$(cd "${VIM_SOURCE_DIR}" \
-      && git log -1 --format="%H" "${vim_version}")
+    vim_commit_ref="$vim_version"
     local munge_commit_line=false
   fi
 
+  vim_commit=$(git -C "${VIM_SOURCE_DIR}" log -1 --format="%H" "${vim_commit_ref}" --) || {
+    >&2 msg_err "Couldn't find Vim revision '${vim_commit_ref}'."
+    exit 3
+  }
+
   vim_commit_url="https://github.com/vim/vim/commit/${vim_commit}"
-  vim_message="$(cd "${VIM_SOURCE_DIR}" \
-    && git log -1 --pretty='format:%B' "${vim_commit}" \
+  vim_message="$(git -C "${VIM_SOURCE_DIR}" log -1 --pretty='format:%B' "${vim_commit}" \
       | sed -e 's/\(#[0-9]\{1,\}\)/vim\/vim\1/g')"
   if [[ ${munge_commit_line} == "true" ]]; then
     # Remove first line of commit message.
@@ -198,10 +217,6 @@ get_vimpatch() {
   LC_ALL=C sed -e 's@\( [ab]/runtime\)/colors/\(tools/check_colors.vim\)@\1/\2@g' \
     "$file" > "$file".tmp && mv "$file".tmp "$file"
 }
-
-get_vimpatch() {
-  get_vim_sources
-
 
 get_vimpatch() {
   get_vim_sources
@@ -357,7 +372,7 @@ submit_pr() {
       continue
     fi
     rm -- "${NVIM_SOURCE_DIR}/${patch_file}"
-    msg_ok "Removed '${NVIM_SOURCE_DIR}/${patch_file}'."
+    msg_ok "Removed '${NVIM_SOURCE_DIR}/${patch_file}'."
   done
 }
 
@@ -380,6 +395,7 @@ list_vimpatch_numbers() {
 # a "vim-patch:xxx" token in the Nvim git log.
 list_vimpatch_numbers() {
   # Transform "vim-patch:X.Y.ZZZZ" to "ZZZZ".
+  list_vimpatch_tokens | while read -r vimpatch_token; do
     echo "$vimpatch_token" | grep '8\.0\.' | sed 's/.*vim-patch:8\.0\.\([0-9a-z]\+\).*/\1/'
   done
 }
@@ -404,7 +420,7 @@ list_missing_vimpatches() {
       --shell)
   )"
   # Exit in case of errors from the above eval (empty vim_commit_tags).
-  if ! (( "${#vim_commit_tags[@]}" )); then
+  if ! (( "${#vim_commit_tags[@]}" )); then
     msg_err "Could not get Vim commits/tags."
     exit 1
   fi
@@ -435,7 +451,7 @@ show_vimpatches() {
 show_vimpatches() {
   get_vim_sources
   printf "\nVim patches missing from Neovim:\n"
-
+
   local -A runtime_commits
   for commit in $(git -C "${VIM_SOURCE_DIR}" log --format="%H %D" -- runtime | sed 's/,\? tag: / /g'); do
     runtime_commits[$commit]=1
@@ -561,11 +577,13 @@ while getopts "hlLMVp:P:g:r:s" opt; do
 }
 
 while getopts "hlLMVp:P:g:r:s" opt; do
-  case ${opt} in
+  case ${opt} in
+    h)
       usage
       exit 0
       ;;
-      ;;
+    l)
+      shift  # remove opt
       show_vimpatches "$@"
       exit 0
       ;;