fix(vcs_info): avoid undefining wrapper during load transition

Co-authored-by: robbyrussell <257+robbyrussell@users.noreply.github.com>
fix(vcs_info): keep lazy wrapper recoverable on autoload failure
2026-09-21 18:46:06 +02:00 · 2026-09-06 15:56:08 +00:00 · 2026-09-06 15:55:21 +00:00 · 2026-09-06 15:54:56 +00:00 · 2026-09-06 08:14:53 -07:00
1 changed files with 42 additions and 11 deletions
@@ -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 $tmp here because it's already a local variable in VCS_INFO_formats
-typeset PATCH='for tmp (base base-name branch misc revision subdir) hook_com[$tmp]="${hook_com[$tmp]//\%/%%}"'
-# Unique string to avoid reapplying the patch if this code gets called twice
-typeset 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}'
+    # 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}; ${MATCH}'
+    fi
+  }
+else
+  function VCS_INFO_formats {
+    local loaded_function="$(
+      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
Author	SHA1	Message	Date
copilot-swe-agent[bot]androbbyrussell	61f12e078f	fix(vcs_info): avoid undefining wrapper during load transition Co-authored-by: robbyrussell <257+robbyrussell@users.noreply.github.com>	2026-09-06 15:56:08 +00:00
copilot-swe-agent[bot]androbbyrussell	e4172614e8	fix(vcs_info): keep lazy wrapper recoverable on autoload failure Co-authored-by: robbyrussell <257+robbyrussell@users.noreply.github.com>	2026-09-06 15:55:21 +00:00
copilot-swe-agent[bot]androbbyrussell	3fe8d6d6af	fix(vcs_info): preserve preloaded VCS_INFO_formats when patching Co-authored-by: robbyrussell <257+robbyrussell@users.noreply.github.com>	2026-09-06 15:54:56 +00:00
Robby RussellandClaude Fable 5.1	a0fa610df3	perf(vcs_info): apply the %-quoting patch on first use lib/vcs_info.zsh loaded VCS_INFO_formats and regexp-replace and patched the function body on every startup, although only themes that call vcs_info ever need it. Define a VCS_INFO_formats wrapper that loads and patches the real function the first time it's called, then replaces itself with it. `autoload` doesn't override an existing function, so the wrapper survives a theme's `autoload -Uz vcs_info` and vcs_info's own autoload of VCS_INFO_*. Verified that a branch named `evil%n%m` still renders literally after prompt expansion, as with the eager patch (CVE-2021-45444 mitigation). Measured on macOS arm64, zsh 5.9: 1.6 ms -> 0.1 ms per interactive start. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>	2026-09-06 08:14:53 -07:00