Do not bind empty key entries.

keyboard.zsh

@@ -58,26 +58,37 @@ if zstyle -m ':omz:editor' keymap 'emacs'; then
   # Use Emacs key bindings.
   bindkey -e
 
+  [[ -n "$keyinfo[Escape]" ]] && \
     bindkey "$keyinfo[Escape]b" emacs-backward-word
+  [[ -n "$keyinfo[Escape]" ]] && \
     bindkey "$keyinfo[Escape]f" emacs-forward-word
+  [[ -n "$keyinfo[Escape]" ]] && [[ -n "$keyinfo[Left]" ]] && \
     bindkey "$keyinfo[Escape]$keyinfo[Left]" emacs-backward-word
+  [[ -n "$keyinfo[Escape]" ]] && [[ -n "$keyinfo[Right]" ]] && \
     bindkey "$keyinfo[Escape]$keyinfo[Right]" emacs-forward-word
 
   # Kill to the beginning of the line.
+  [[ -n "$keyinfo[Control]" ]] && \
     bindkey "$keyinfo[Control]u" backward-kill-line
 
   # Kill to the beginning of the word.
+  [[ -n "$keyinfo[Control]" ]] && \
     bindkey "$keyinfo[Control]w" backward-kill-word
 
   # Undo/Redo
+  [[ -n "$keyinfo[Control]" ]] && \
     bindkey "$keyinfo[Control]_" undo
+  [[ -n "$keyinfo[Escape]" ]] && \
     bindkey "$keyinfo[Escape]_" redo
 
   # Search character.
+  [[ -n "$keyinfo[Control]" ]] && \
     bindkey "$keyinfo[Control]]" vi-find-next-char
+  [[ -n "$keyinfo[Escape]" ]] && [[ -n "$keyinfo[Control]" ]] && \
     bindkey "$keyinfo[Escape]$keyinfo[Control]]" vi-find-prev-char
 
   # Edit command in an external editor.
+  [[ -n "$keyinfo[Control]" ]] && \
     bindkey "$keyinfo[Control]x$keyinfo[Control]e" edit-command-line
 
   # Expand .... to ../..
@@ -88,10 +99,14 @@ if zstyle -m ':omz:editor' keymap 'emacs'; then
   # Bind to history substring search plugin if enabled;
   # otherwise, bind to built-in Zsh history search.
   if (( $+widgets[history-incremental-pattern-search-backward] )); then
+    [[ -n "$keyinfo[Control]" ]] && \
       bindkey "$keyinfo[Control]r" history-incremental-pattern-search-backward
+    [[ -n "$keyinfo[Control]" ]] && \
       bindkey "$keyinfo[Control]s" history-incremental-pattern-search-forward
   else
+    [[ -n "$keyinfo[Control]" ]] && \
       bindkey "$keyinfo[Control]r" history-incremental-search-backward
+    [[ -n "$keyinfo[Control]" ]] && \
       bindkey "$keyinfo[Control]s" history-incremental-search-forward
   fi
 elif zstyle -m ':omz:editor' keymap 'vi'; then
@@ -140,6 +155,7 @@ elif zstyle -m ':omz:editor' keymap 'vi'; then
 
   # Undo/Redo
   bindkey -M vicmd "u" undo
+  [[ -n "$keyinfo[Control]" ]] && \
     bindkey -M vicmd "$keyinfo[Control]r" redo
 
   # Expand .... to ../..
@@ -152,20 +168,35 @@ elif zstyle -m ':omz:editor' keymap 'vi'; then
   bindkey -M viins "kj" vi-cmd-mode
 
   # Emacs key bindings in insert mode.
+  [[ -n "$keyinfo[Control]" ]] && \
     bindkey -M viins "$keyinfo[Control]a" beginning-of-line
+  [[ -n "$keyinfo[Control]" ]] && \
     bindkey -M viins "$keyinfo[Control]b" backward-char
+  [[ -n "$keyinfo[Escape]" ]] && \
     bindkey -M viins "$keyinfo[Escape]b" emacs-backward-word
+  [[ -n "$keyinfo[Control]" ]] && \
     bindkey -M viins "$keyinfo[Control]d" delete-char-or-list
+  [[ -n "$keyinfo[Escape]" ]] && \
     bindkey -M viins "$keyinfo[Escape]d" kill-word
+  [[ -n "$keyinfo[Control]" ]] && \
     bindkey -M viins "$keyinfo[Control]e" end-of-line
+  [[ -n "$keyinfo[Control]" ]] && \
     bindkey -M viins "$keyinfo[Control]f" forward-char
+  [[ -n "$keyinfo[Escape]" ]] && \
     bindkey -M viins "$keyinfo[Escape]f" emacs-forward-word
+  [[ -n "$keyinfo[Control]" ]] && \
     bindkey -M viins "$keyinfo[Control]k" kill-line
+  [[ -n "$keyinfo[Control]" ]] && \
     bindkey -M viins "$keyinfo[Control]u" backward-kill-line
+  [[ -n "$keyinfo[Control]" ]] && \
     bindkey -M viins "$keyinfo[Control]w" backward-kill-word
+  [[ -n "$keyinfo[Escape]" ]] && \
     bindkey -M viins "$keyinfo[Escape]w" copy-region-as-kill
+  [[ -n "$keyinfo[Escape]" ]] && \
     bindkey -M viins "$keyinfo[Escape]h" run-help
+  [[ -n "$keyinfo[Escape]" ]] && [[ -n "$keyinfo[Left]" ]] && \
     bindkey -M viins "$keyinfo[Escape]$keyinfo[Left]" emacs-backward-word
+  [[ -n "$keyinfo[Escape]" ]] && [[ -n "$keyinfo[Right]" ]] && \
     bindkey -M viins "$keyinfo[Escape]$keyinfo[Right]" emacs-forward-word
 
   # History
@@ -187,14 +218,18 @@ elif zstyle -m ':omz:editor' keymap 'vi'; then
     bindkey -M vicmd "/" history-incremental-pattern-search-forward
 
     # Emacs key bindings in insert mode.
+    [[ -n "$keyinfo[Control]" ]] && \
       bindkey -M viins "$keyinfo[Control]r" history-incremental-pattern-search-backward
+    [[ -n "$keyinfo[Control]" ]] && \
       bindkey -M viins "$keyinfo[Control]s" history-incremental-pattern-search-forward
   else
     bindkey -M vicmd "?" history-incremental-search-backward
     bindkey -M vicmd "/" history-incremental-search-forward
 
     # Emacs key bindings in insert mode.
+    [[ -n "$keyinfo[Control]" ]] && \
       bindkey -M viins "$keyinfo[Control]r" history-incremental-search-backward
+    [[ -n "$keyinfo[Control]" ]] && \
       bindkey -M viins "$keyinfo[Control]s" history-incremental-search-forward
   fi
 else
@@ -203,44 +238,64 @@ else
 fi
 
 # The next key bindings are for both Emacs and Vi.
+[[ -n "$keyinfo[Home]" ]] && \
   bindkey "$keyinfo[Home]" beginning-of-line
+[[ -n "$keyinfo[End]" ]] && \
   bindkey "$keyinfo[End]" end-of-line
 
+[[ -n "$keyinfo[Insert]" ]] && \
   bindkey "$keyinfo[Insert]" overwrite-mode
+[[ -n "$keyinfo[Delete]" ]] && \
   bindkey "$keyinfo[Delete]" delete-char
+[[ -n "$keyinfo[Backspace]" ]] && \
   bindkey "$keyinfo[Backspace]" backward-delete-char
 
+[[ -n "$keyinfo[Left]" ]] && \
   bindkey "$keyinfo[Left]" backward-char
+[[ -n "$keyinfo[Right]" ]] && \
   bindkey "$keyinfo[Right]" forward-char
 
 # Expand history on space.
 bindkey ' ' magic-space
 
 if (( $+plugins[(er)history-substring-search] )); then
+  [[ -n "$keyinfo[Up]" ]] && \
     bindkey "$keyinfo[Up]" history-substring-search-up
+  [[ -n "$keyinfo[Down]" ]] && \
     bindkey "$keyinfo[Down]" history-substring-search-down
+  [[ -n "$keyinfo[Control]" ]] && \
     bindkey "$keyinfo[Control]p" history-substring-search-up
+  [[ -n "$keyinfo[Control]" ]] && \
     bindkey "$keyinfo[Control]n" history-substring-search-down
 else
+  [[ -n "$keyinfo[Up]" ]] && \
     bindkey "$keyinfo[Up]" up-line-or-history
+  [[ -n "$keyinfo[Down]" ]] && \
     bindkey "$keyinfo[Down]" down-line-or-history
+  [[ -n "$keyinfo[Control]" ]] && \
     bindkey "$keyinfo[Control]p" up-line-or-history
+  [[ -n "$keyinfo[Control]" ]] && \
     bindkey "$keyinfo[Control]n" down-line-or-history
 fi
 
 # Clear screen.
+[[ -n "$keyinfo[Control]" ]] && \
   bindkey "$keyinfo[Control]l" clear-screen
 
 # Expand command name to full path.
+[[ -n "$keyinfo[Escape]" ]] && \
   bindkey "$keyinfo[Escape]e" expand-cmd-path
 
 # Duplicate the previous word.
+[[ -n "$keyinfo[Escape]" ]] && \
   bindkey "$keyinfo[Escape]m" copy-prev-shell-word
 
 # Bind Shift + Tab to go to the previous menu item.
+[[ -n "$keyinfo[BackTab]" ]] && \
   bindkey "$keyinfo[BackTab]" reverse-menu-complete
 
 # Complete in the middle of word.
+[[ -n "$keyinfo[Control]" ]] && \
   bindkey "$keyinfo[Control]i" expand-or-complete-prefix
 
 # Convert .... to ../.. automatically.
@@ -266,5 +321,6 @@ function expand-or-complete-prefix-with-indicator() {
   zle redisplay
 }
 zle -N expand-or-complete-prefix-with-indicator
+[[ -n "$keyinfo[Control]" ]] && \
   bindkey "$keyinfo[Control]i" expand-or-complete-prefix-with-indicator