[zsh] improve compdump handling when initializing the completion system

zsh/plugins.zsh

@@ -4,10 +4,33 @@ source "$ZSH_DOTFILES/zplg.zsh"
 
 plugin completions 'zsh-users/zsh-completions'
 
-# Oh-My-Zsh {{{
+run_compinit() {
+  autoload -U compinit
 
-  # initialize the completion system
-  autoload -Uz compinit && compinit -C
+  local match run_compdump=1
+  # glob qualifiers description:
+  #   N    turn on NULL_GLOB for this expansion
+  #   .    match only plain files
+  #   m-1  check if the file was modified today
+  # see "Filename Generation" in zshexpn(1)
+  for match in $HOME/.zcompdump(N.m-1); do
+    run_compdump=
+    break
+  done
+
+  if [[ -n "$run_compdump" ]]; then
+    # -D flag turns off compdump loading
+    compinit -D
+    compdump
+  else
+    # -C flag disables some checks performed by compinit - they are not needed
+    # because we already have a fresh compdump
+    compinit -C
+  fi
+}
+run_compinit
+
+# Oh-My-Zsh {{{
 
   ZSH_CACHE_DIR="$ZSH_DOTFILES/cache"