vim-patch.sh: list related missing Vim patches [ci skip] #11514

* scripts/vim-patch.sh: factor out _set_tokens_and_tags

This allows for caching `$tokens` and `$vim_commit_tags`, which will
become relevant with the next commit adding
`list_missing_previous_vimpatches_for_patch`.

scripts/vim-patch.sh

@@ -395,13 +395,48 @@ list_vimpatch_numbers() {
 # Prints all patch-numbers (for the current v:version) for which there is
 # 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
+}
+
+declare -A tokens
+declare -A vim_commit_tags
+
+_set_tokens_and_tags() {
+  if [[ -n "${tokens[*]}" ]]; then
+    return
+  fi
+
+  # Find all "vim-patch:xxx" tokens in the Nvim git log.
+  for token in $(list_vimpatch_tokens); do
+    tokens[$token]=1
+  done
+
+  # Create an associative array mapping Vim commits to tags.
+  eval "vim_commit_tags=(
+    $(git -C "${VIM_SOURCE_DIR}" for-each-ref refs/tags \
+      --format '[%(objectname)]=%(refname:strip=2)' \
+      --sort='-*authordate' \
+      --shell)
+  )"
+  # Exit in case of errors from the above eval (empty vim_commit_tags).
   if ! (( "${#vim_commit_tags[@]}" )); then
     msg_err "Could not get Vim commits/tags."
     exit 1
   fi
+}
+
+# Prints a newline-delimited list of Vim commits, for use by scripts.
+# "$1": use extended format?
+# "$@" is passed to list_vim_commits, as extra arguments to git-log.
+list_missing_vimpatches() {
+  local -a missing_vim_patches=()
+  _set_missing_vimpatches "$@"
+  for line in "${missing_vim_patches[@]}"; do
+    printf '%s\n' "$line"
   done
-
-# Prints a newline-delimited list of Vim commits, for use by scripts.
 }
 
 # Sets / appends to missing_vim_patches (useful to avoid a subshell when
@@ -416,6 +451,7 @@ list_missing_vimpatches() {
   else
     git_log_args=("--format=%H")
   fi
+
   # Massage arguments for git-log.
   declare -A git_log_replacements=(
     [^\(.*/\)?src/nvim/\(.*\)]="\${BASH_REMATCH[1]}src/\${BASH_REMATCH[2]}"
@@ -426,23 +462,7 @@ list_missing_vimpatches() {
     for j in "${!git_log_replacements[@]}"; do
       if [[ "$i" =~ $j ]]; then
         eval "git_log_args+=(${git_log_replacements[$j]})"
-        continue 2
-      fi
-    done
-    git_log_args+=("$i")
-  done
-
-  # Find all "vim-patch:xxx" tokens in the Nvim git log.
-  for token in $(list_vimpatch_tokens); do
-    tokens[$token]=1
-  done
-
-  # Create an associative array mapping Vim commits to tags.
-  eval "declare -A vim_commit_tags=(
-    $(git -C "${VIM_SOURCE_DIR}" for-each-ref refs/tags \
-      --format '[%(objectname)]=%(refname:strip=2)' \
-      --sort='-*authordate' \
-      --shell)
+        continue 2
       fi
     done
     git_log_args+=("$i")
@@ -474,9 +494,9 @@ list_missing_vimpatches() {
     fi
 
     vim_tag="${vim_commit_tags[$vim_commit]-}"
-    if [[ -n "$vim_tag" ]]; then
+    if [[ -n "$vim_tag" ]]; then
       # Check for vim-patch:<tag> (not commit hash).
-      patch_number="vim-patch:${vim_tag:1}" # "v7.4.0001" => "7.4.0001"
+      patch_number="vim-patch:${vim_tag:1}" # "v7.4.0001" => "7.4.0001"
       if [[ "${tokens[$patch_number]-}" ]]; then
         continue
       fi
@@ -512,6 +532,59 @@ Instructions:
 Instructions:
   To port one of the above patches to Neovim, execute this script with the patch revision as argument and follow the instructions, e.g.
   '${BASENAME} -p v8.0.1234', or '${BASENAME} -P v8.0.1234'
+
+  NOTE: Please port the _oldest_ patch if you possibly can.
+        You can use '${BASENAME} -l path/to/file' to see what patches are missing for a file.
+EOF
+}
+
+list_missing_previous_vimpatches_for_patch() {
+  local for_vim_patch="${1}"
+  local vim_commit vim_tag
+  assign_commit_details "${for_vim_patch}"
+
+  local file
+  local -a missing_list
+  local -a fnames
+  while IFS= read -r line ; do
+    fnames+=("$line")
+  done < <(git -C "${VIM_SOURCE_DIR}" diff-tree --no-commit-id --name-only -r "${vim_commit}")
+  local i=0
+  local n=${#fnames[@]}
+  printf '=== getting missing patches for %d files ===\n' "$n"
+  if [[ -z "${vim_tag}" ]]; then
+    printf 'NOTE: "%s" is not a Vim tag - listing all oldest missing patches\n' "${for_vim_patch}" >&2
+  fi
+  for fname in "${fnames[@]}"; do
+    i=$(( i+1 ))
+    printf '[%.*d/%d] %s: ' "${#n}" "$i" "$n" "$fname"
+
+    local -a missing_vim_patches=()
+    _set_missing_vimpatches 1 -- "${fname}"
+
+    local missing_vim_commit_info="${missing_vim_patches[0]}"
+    if [[ -z "${missing_vim_commit_info}" ]]; then
+      printf -- "-\n"
+    else
+      local missing_vim_commit="${missing_vim_commit_info%%:*}"
+      if [[ -z "${vim_tag}" ]] || [[ "${missing_vim_commit}" < "${vim_tag}" ]]; then
+        printf -- "%s\n" "$missing_vim_commit_info"
+        missing_list+=("$missing_vim_commit_info")
+      else
+        printf -- "-\n"
+      fi
+    fi
+  done
+
+  if [[ -z "${missing_list[*]}" ]]; then
+    msg_ok 'no missing previous Vim patches'
+    return 0
+  fi
+
+  local -a missing_unique
+  while IFS= read -r line; do
+    missing_unique+=("$line")
+  done < <(printf '%s\n' "${missing_list[@]}" | sort -u)
 
   msg_err "$(printf '%d missing previous Vim patches:' ${#missing_unique[@]})"
   printf ' - %s\n' "${missing_unique[@]}"
@@ -609,7 +682,7 @@ review_pr() {
       if [[ "${reply}" == n ]]; then
         break
       fi
-    fi
+    fi
   done
 
   clean_files
@@ -629,6 +702,11 @@ while getopts "hlLMVp:P:g:r:s" opt; do
     L)
       shift  # remove opt
       list_missing_vimpatches 0 "$@"
+      exit 0
+      ;;
+    M)
+      list_vimpatch_numbers
+      exit 0
       ;;
     m)
       shift  # remove opt