win32: special treatment for PATH

The PATH shell variable is a special case.  It can be exported to
the environment where it might be interpreted by native applications
which assume the separator is ';'.  Hence:

- require that the separator used in PATH is ';'
- enforce this by intercepting calls to setvareq() that set PATH
  and adjusting its value if necessary.

As a result of this the code to parse PATH can be simplified by
replacing the hardcoded Unix ':' path separator by the platform-
dependent macro PATH_SEP.

The MANPATH variable is also required to use ';' as its separator
but since it's less likely to be used this isn't enforced.

1 files changed, 4 insertions, 11 deletions

diff --git a/libbb/executable.c b/libbb/executable.c
index 835341ed9..87a40eeda 100644
--- a/libbb/executable.c
+++ b/libbb/executable.c
@@ -40,28 +40,21 @@ char* FAST_FUNC find_executable(const char *filename, char **PATHp)
          */
         char *p, *n;
 #if ENABLE_PLATFORM_MINGW32
-        char sep, *w;
+        char *w;
 #endif
 
         p = *PATHp;
         while (p) {
                 int ex;
 
-#if !ENABLE_PLATFORM_MINGW32
-                n = strchr(p, ':');
+                n = strchr(p, PATH_SEP);
                 if (n) *n = '\0';
-#else
-                n = (char*)next_path_sep(p);
-                if (n) { sep = *n; *n = '\0'; }
-#endif
                 p = concat_path_file(
                         p[0] ? p : ".", /* handle "::" case */
                         filename
                 );
-#if !ENABLE_PLATFORM_MINGW32
-                if (n) *n++ = ':';
-#else
-                if (n) *n++ = sep;
+                if (n) *n++ = PATH_SEP;
+#if ENABLE_PLATFORM_MINGW32
                 if ((w=alloc_win32_extension(p))) {
                         free(p);
                         p = w;