Overload fish_wcstod for wcstring and length

This lets us skip wcslen a bunch

src/builtins/test.cpp

@@ -669,13 +669,14 @@ bool parenthetical_expression::evaluate(io_streams_t *streams, wcstring_list_t &
 }
 
 // Parse a double from arg. Return true on success, false on failure.
-static bool parse_double(const wchar_t *arg, double *out_res) {
+static bool parse_double(const wcstring &argstr, double *out_res) {
     // Consume leading spaces.
+    const wchar_t *arg = argstr.c_str();
     while (arg && *arg != L'\0' && iswspace(*arg)) arg++;
     if (!arg) return false;
     errno = 0;
     wchar_t *end = nullptr;
-    *out_res = fish_wcstod(arg, &end);
+    *out_res = fish_wcstod(arg, &end, argstr.size() - (arg - argstr.c_str()));
     // Consume trailing spaces.
     while (end && *end != L'\0' && iswspace(*end)) end++;
     return errno == 0 && end > arg && *end == L'\0';
@@ -688,7 +689,7 @@ static bool parse_double(const wchar_t *arg, double *out_res) {
 static bool parse_number(const wcstring &arg, number_t *number, wcstring_list_t &errors) {
     const wchar_t *argcs = arg.c_str();
     double floating = 0;
-    bool got_float = parse_double(argcs, &floating);
+    bool got_float = parse_double(arg, &floating);
     errno = 0;
     long long integral = fish_wcstoll(argcs);
     bool got_int = (errno == 0);

src/env_dispatch.cpp

@@ -445,7 +445,7 @@ static void update_fish_color_support(const environment_t &vars) {
                 FLOGF(term_support, L"Truecolor support: Enabling for st");
                 support_term24bit = true;
             } else if (auto vte = vars.get(L"VTE_VERSION")) {
-                if (fish_wcstod(vte->as_string().c_str(), nullptr) > 3600) {
+                if (fish_wcstod(vte->as_string(), nullptr) > 3600) {
                     FLOGF(term_support, L"Truecolor support: Enabling for VTE version %ls",
                           vte->as_string().c_str());
                     support_term24bit = true;

src/wutil.cpp

@@ -692,11 +692,10 @@ unsigned long long fish_wcstoull(const wchar_t *str, const wchar_t **endptr, int
 
 /// Like wcstod(), but wcstod() is enormously expensive on some platforms so this tries to have a
 /// fast path.
-double fish_wcstod(const wchar_t *str, wchar_t **endptr) {
+double fish_wcstod(const wchar_t *str, wchar_t **endptr, size_t len) {
     // We can ignore the locale because we use LC_NUMERIC=C!
     // The "fast path." If we're all ASCII and we fit inline, use strtod().
     char narrow[128];
-    size_t len = std::wcslen(str);
     size_t len_plus_0 = 1 + len;
     auto is_ascii = [](wchar_t c) { return 0 <= c && c <= 127; };
     if (len_plus_0 <= sizeof narrow && std::all_of(str, str + len, is_ascii)) {
@@ -713,6 +712,13 @@ double fish_wcstod(const wchar_t *str, wchar_t **endptr) {
     return std::wcstod(str, endptr);
 }
 
+double fish_wcstod(const wchar_t *str, wchar_t **endptr) {
+    return fish_wcstod(str, endptr, std::wcslen(str));
+}
+double fish_wcstod(const wcstring &str, wchar_t **endptr) {
+    return fish_wcstod(str.c_str(), endptr, str.size());
+}
+
 /// Like wcstod(), but allows underscore separators. Leading, trailing, and multiple underscores are
 /// allowed, as are underscores next to decimal (.), exponent (E/e/P/p), and hexadecimal (X/x)
 /// delimiters. This consumes trailing underscores -- endptr will point past the last underscore

src/wutil.h

@@ -132,7 +132,9 @@ long fish_wcstol(const wchar_t *str, const wchar_t **endptr = nullptr, int base
 long long fish_wcstoll(const wchar_t *str, const wchar_t **endptr = nullptr, int base = 10);
 unsigned long long fish_wcstoull(const wchar_t *str, const wchar_t **endptr = nullptr,
                                  int base = 10);
+double fish_wcstod(const wchar_t *str, wchar_t **endptr, size_t len);
 double fish_wcstod(const wchar_t *str, wchar_t **endptr);
+double fish_wcstod(const wcstring &str, wchar_t **endptr);
 double fish_wcstod_underscores(const wchar_t *str, wchar_t **endptr);
 
 /// Class for representing a file's inode. We use this to detect and avoid symlink loops, among