fix(vcs_info): avoid undefining wrapper during load transition

Co-authored-by: robbyrussell <257+robbyrussell@users.noreply.github.com>

lib/vcs_info.zsh

@@ -38,16 +38,47 @@
 # due to malicious input as a consequence of CVE-2021-45444, which affects
 # zsh versions from 5.0.3 to 5.8.
 #
-autoload -Uz +X regexp-replace VCS_INFO_formats 2>/dev/null || return 0
+# The patch is applied when VCS_INFO_formats is first called, since loading
+# and patching it on every startup costs time in shells that never use
+# vcs_info. `autoload` doesn't replace an already defined function, so this
+# wrapper survives a later `autoload -Uz vcs_info` in a theme or .zshrc, and
+# vcs_info's own `autoload -Uz VCS_INFO_formats`.
+if (( $+functions[VCS_INFO_formats] )); then
+  () {
+    autoload -Uz +X regexp-replace 2>/dev/null || return 1
 
-# We use $tmp here because it's already a local variable in VCS_INFO_formats
+    # We use $tmp here because it's already a local variable in VCS_INFO_formats
-typeset PATCH='for tmp (base base-name branch misc revision subdir) hook_com[$tmp]="${hook_com[$tmp]//\%/%%}"'
+    local PATCH='for tmp (base base-name branch misc revision subdir) hook_com[$tmp]="${hook_com[$tmp]//\%/%%}"'
-# Unique string to avoid reapplying the patch if this code gets called twice
+    # Unique string to avoid reapplying the patch if this code gets called twice
-typeset PATCH_ID=vcs_info-patch-9b9840f2-91e5-4471-af84-9e9a0dc68c1b
+    local PATCH_ID=vcs_info-patch-9b9840f2-91e5-4471-af84-9e9a0dc68c1b
-# Only patch the VCS_INFO_formats function if not already patched
+    # Only patch the VCS_INFO_formats function if not already patched
-if [[ "$functions[VCS_INFO_formats]" != *$PATCH_ID* ]]; then
+    if [[ "$functions[VCS_INFO_formats]" != *$PATCH_ID* ]]; then
-  regexp-replace 'functions[VCS_INFO_formats]' \
+      regexp-replace 'functions[VCS_INFO_formats]' \
-    "VCS_INFO_hook 'post-backend'" \
+        "VCS_INFO_hook 'post-backend'" \
-    ': ${PATCH_ID}; ${PATCH}; ${MATCH}'
+        ': ${PATCH_ID}; ${PATCH}; ${MATCH}'
+    fi
+  }
+else
+  function VCS_INFO_formats {
+    local loaded_function="$(
+      unfunction VCS_INFO_formats 2>/dev/null
+      autoload -Uz +X VCS_INFO_formats 2>/dev/null || return 1
+      print -r -- "$functions[VCS_INFO_formats]"
+    )" || return 1
+    functions[VCS_INFO_formats]="$loaded_function"
+    autoload -Uz +X regexp-replace 2>/dev/null || return 1
+
+    # We use $tmp here because it's already a local variable in VCS_INFO_formats
+    local PATCH='for tmp (base base-name branch misc revision subdir) hook_com[$tmp]="${hook_com[$tmp]//\%/%%}"'
+    # Unique string to avoid reapplying the patch if this code gets called twice
+    local PATCH_ID=vcs_info-patch-9b9840f2-91e5-4471-af84-9e9a0dc68c1b
+    # Only patch the VCS_INFO_formats function if not already patched
+    if [[ "$functions[VCS_INFO_formats]" != *$PATCH_ID* ]]; then
+      regexp-replace 'functions[VCS_INFO_formats]' \
+        "VCS_INFO_hook 'post-backend'" \
+        ': ${PATCH_ID}; ${PATCH}; ${MATCH}'
+    fi
+
+    VCS_INFO_formats "$@"
+  }
 fi
-unset PATCH PATCH_ID

oh-my-zsh.sh

@@ -100,23 +100,7 @@ done
 # Figure out the SHORT hostname
 if [[ "$OSTYPE" = darwin* ]]; then
   # macOS's $HOST changes with dhcp, etc. Use LocalHostName if possible.
-  # scutil costs a fork on every start, so remember its answer for a day
+  SHORT_HOST=$(scutil --get LocalHostName 2>/dev/null) || SHORT_HOST="${HOST/.*/}"
-  # (like lib/grep.zsh) and re-check sooner if $HOST changes.
-  __omz_host_cache="$ZSH_CACHE_DIR/localhostname"
-  __omz_host_cached=("$__omz_host_cache"(Nm-1))
-  if [[ -n "$__omz_host_cached" ]]; then
-    { read -r __omz_host_key && read -r SHORT_HOST } < "$__omz_host_cache"
-  fi
-  if [[ "$__omz_host_key" != "$HOST" || -z "$SHORT_HOST" ]]; then
-    # only cache what scutil actually answered, so a transient failure
-    # doesn't pin the fallback name for a day
-    if SHORT_HOST=$(scutil --get LocalHostName 2>/dev/null) && [[ -n "$SHORT_HOST" ]]; then
-      [[ ! -w "$ZSH_CACHE_DIR" ]] || print -rl -- "$HOST" "$SHORT_HOST" >| "$__omz_host_cache"
-    else
-      SHORT_HOST="${HOST/.*/}"
-    fi
-  fi
-  unset __omz_host_cache __omz_host_cached __omz_host_key
 else
   SHORT_HOST="${HOST/.*/}"
 fi