fix(git): force C locale only while matching status regexes (#14006)

lib/git.zsh

@@ -39,16 +39,27 @@ function _omz_git_prompt_info() {
   echo "${ZSH_THEME_GIT_PROMPT_PREFIX}${ref//\%/%%}${upstream//\%/%%}$(parse_git_dirty)${ZSH_THEME_GIT_PROMPT_SUFFIX}"
 }
 
-function _omz_git_prompt_status() {
-  # OHMYZSH-13330: avoid "regex matching error: illegal byte sequence".
-  # zsh's "=~" operator delegates to the C library regex, which aborts with
-  # REG_ILLSEQ when the subject contains an invalid byte sequence under a
-  # multibyte locale (e.g. a filename with non-UTF-8 bytes in `git status`
-  # output). Forcing the C locale makes every byte a valid character, so the
-  # regex matching below never fails that way. `git status --porcelain` is
-  # locale-independent, so this does not change the parsed output.
+# Match an extended regular expression against a subject, forcing the C locale
+# only for the duration of the call.
+#
+# OHMYZSH-13330: zsh's "=~" operator delegates to the C library regex, which
+# aborts with REG_ILLSEQ when the subject contains an invalid byte sequence
+# under a multibyte locale (e.g. a filename with non-UTF-8 bytes in `git
+# status` output). Forcing the C locale makes every byte a valid character,
+# so the regex matching never fails that way. `git status --porcelain` is
+# locale-independent, so this does not change the parsed output.
+#
+# OHMYZSH-13985: the locale must be scoped to this function and not set for
+# the whole caller. Assigning LC_ALL makes zsh re-run setlocale() right away,
+# so leaving it set while the rest of the caller runs breaks multibyte
+# handling there — most visibly, `echo` refuses to expand Unicode escapes in
+# theme prompt symbols ("character not in range").
+function _omz_git_prompt_status_match() {
   local -x LC_ALL=C
+  [[ "$1" =~ "$2" ]]
+}
 
+function _omz_git_prompt_status() {
   [[ "$(__git_prompt_git config --get oh-my-zsh.hide-status 2>/dev/null)" = 1 ]] && return
 
   # Maps a git status prefix to an internal constant
@@ -113,11 +124,11 @@ function _omz_git_prompt_status() {
   status_lines=("${(@f)${status_text}}")
 
   # If the tracking line exists, get and parse it
-  if [[ "$status_lines[1]" =~ "^## [^ ]+ \[(.*)\]" ]]; then
+  if _omz_git_prompt_status_match "$status_lines[1]" "^## [^ ]+ \[(.*)\]"; then
     local branch_statuses
     branch_statuses=("${(@s/,/)match}")
     for branch_status in $branch_statuses; do
-      if [[ ! $branch_status =~ "(behind|diverged|ahead) ([0-9]+)?" ]]; then
+      if ! _omz_git_prompt_status_match "$branch_status" "(behind|diverged|ahead) ([0-9]+)?"; then
         continue
       fi
       local last_parsed_status=$prefix_constant_map[$match[1]]
@@ -130,7 +141,7 @@ function _omz_git_prompt_status() {
     local status_constant="${prefix_constant_map[$status_prefix]}"
     local status_regex=$'(^|\n)'"$status_prefix"
 
-    if [[ "$status_text" =~ $status_regex ]]; then
+    if _omz_git_prompt_status_match "$status_text" "$status_regex"; then
       statuses_seen[$status_constant]=1
     fi
   done