1 files changed, 21 insertions, 6 deletions

diff --git a/libbb/appletlib.c b/libbb/appletlib.c
index 379d6af2f..b5ea90ffd 100644
--- a/libbb/appletlib.c
+++ b/libbb/appletlib.c
@@ -263,18 +263,33 @@ int FAST_FUNC find_applet_by_name(const char *name)
 
 #if ENABLE_PLATFORM_MINGW32 && NUM_APPLETS > 1 && \
                 (ENABLE_FEATURE_PREFER_APPLETS || ENABLE_FEATURE_SH_STANDALONE)
+static int external_exists(const char *name)
+{
+        char *ret = find_first_executable(name);
+        free(ret);
+        return ret != NULL;
+}
+
 int FAST_FUNC is_applet_preferred(const char *name)
 {
-        const char *var, *s;
+        const char *var, *s, *sep;
         size_t len;
 
         var = getenv(BB_OVERRIDE_APPLETS);
         if (var && *var) {
-                /* '-' overrides all applets */
+                /* '-' disables all applets */
                 if (var[0] == '-' && var[1] == '\0')
                         return FALSE;
 
-                /* Override applets from a space-separated list */
+                /* '+' each applet is overridden if an external command exists */
+                if (var[0] == '+' && var[1] == '\0')
+                        return !external_exists(name);
+
+                /* Handle applets from a list separated by spaces, commas or
+                 * semicolons.  Applets before the first semicolon are disabled.
+                 * Applets after the first semicolon are overridden if a
+                 * corresponding external command exists. */
+                sep = strchr(var, ';');
                 len = strlen(name);
                 s = var - 1;
                 while (1) {
@@ -282,12 +297,12 @@ int FAST_FUNC is_applet_preferred(const char *name)
                         if (!s)
                                 break;
                         /* neither "name.." nor "xxx,name.."? */
-                        if (s != var && s[-1] != ' ')
+                        if (s != var && !strchr(" ,;", s[-1]))
                                 continue;
                         /* neither "..name" nor "..name,xxx"? */
-                        if (s[len] != '\0' && s[len] != ' ')
+                        if (s[len] != '\0' && !strchr(" ,;", s[len]))
                                 continue;
-                        return FALSE;
+                        return (sep == NULL || s < sep) ? FALSE : !external_exists(name);
                 }
         }
         return TRUE;