ash: detect native Windows environment on WineFRP-5181-g5c1a3b00e

The shell detected a native Windows environment by checking for a
mixed-case 'Path' environment variable.  This has always worked on
Windows but recent versions of Wine have a 'PATH' environment
variable.

Check also for 'ComSpec'.

Costs 24-48 bytes.

1 files changed, 18 insertions, 2 deletions

diff --git a/shell/ash.c b/shell/ash.c
index 5c4a3073a..41bf45734 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -15801,6 +15801,23 @@ static void setvar_if_unset(const char *key, const char *value)
 }
 #endif
 
+#if ENABLE_PLATFORM_MINGW32
+static int mixed_case_special_name(const char *envp)
+{
+        const char *names = "PATH=\0""COMSPEC=\0";
+        const char *n;
+
+        for (n = names; *n; ) {
+                if (is_prefixed_with_case(envp, n) && !is_prefixed_with(envp, n)) {
+                        return TRUE;
+                }
+                while (*n++)
+                        ;
+        }
+        return FALSE;
+}
+#endif
+
 /* Don't inline: conserve stack of caller from having our locals too */
 static NOINLINE void
 init(void)
@@ -15834,8 +15851,7 @@ init(void)
                  * because it appears first.
                  */
                 for (envp = environ; envp && *envp; envp++) {
-                        if (is_prefixed_with_case(*envp, "PATH=") &&
-                                        !is_prefixed_with(*envp, "PATH=")) {
+                        if (mixed_case_special_name(*envp)) {
                                 break;
                         }
                 }