tools: add shared parent path helper

Move the common parent path extraction helper into tools.c and declare it in
net.h.

Replace the local implementations in RIGHTS, NDIR and NWTESTS with
tool_parent_path(). The helper keeps the existing behavior of uppercasing the
path and preserving a trailing volume colon for parent paths such as SYS:.

No behavior change.

ndir.c

@@ -467,26 +467,6 @@ static int ndir_attr_filter_match(uint32 attr, int options)
   return(match);
 }
 
-static void ndir_parent_path(char *dst, char *src, int max)
-{
-  char tmp[260];
-  char *p;
-
-  tool_upcopy(tmp, src, sizeof(tmp));
-  p = strrchr(tmp, '\\');
-  if (!p) p = strrchr(tmp, ':');
-
-  if (p) {
-    if (*p == ':') {
-      p[1] = '\0';
-    } else {
-      *p = '\0';
-    }
-    strmaxcpy(dst, tmp, max - 1);
-  } else {
-    dst[0] = '\0';
-  }
-}
 
 static void ndir_old_rights_string(uint8 old_rights, char *out)
 {
@@ -627,7 +607,7 @@ static void ndir_effective_rights(char *path, char *out)
     return;
   }
 
-  ndir_parent_path(usepath, path, sizeof(usepath));
+  tool_parent_path(usepath, path, sizeof(usepath));
   newhandle = alloc_temp_dir_handle(dhandle, usepath, 0, &eff_old);
   if (newhandle >= 0) {
     dealloc_dir_handle(newhandle);

net.h

@@ -166,6 +166,7 @@ extern void  tool_header_path(char *out, char *path, int max);
 extern int   tool_is_dot_dir(char *name);
 extern void  tool_join_path(char *out, char *base, char *name, int max);
 extern int   tool_has_wildcards(char *path);
+extern void  tool_parent_path(char *dst, char *src, int max);
 extern void  tool_parent_pattern(char *dir, char *pattern, char *path,
                                  int maxdir, int maxpat);
 

nwtests.c

@@ -91,29 +91,6 @@ static void tests_mask_string(uint8 mask, char *out)
   out[8] = '\0';
 }
 
-static void tests_parent_path(char *dst, char *src, int max)
-{
-  char tmp[260];
-  char *p;
-
-  tool_upcopy(tmp, src, sizeof(tmp));
-  p = strrchr(tmp, '\\');
-  if (!p) p = strrchr(tmp, ':');
-
-  if (!p) {
-    dst[0] = '\0';
-    return;
-  }
-
-  if (*p == ':') {
-    p++;
-    *p = '\0';
-  } else {
-    *p = '\0';
-  }
-
-  strmaxcpy(dst, tmp, max - 1);
-}
 
 static void tests_print_mask(char *label, int rc, uint8 mask)
 {
@@ -2575,7 +2552,7 @@ static int tests_effright(char *path)
     tests_print_eff_row("old handle path", newhandle, 0, 0, 0);
   }
 
-  tests_parent_path(usepath, path, sizeof(usepath));
+  tool_parent_path(usepath, path, sizeof(usepath));
   newhandle = alloc_temp_dir_handle(dhandle, usepath, 0, &eff_old);
   if (newhandle >= 0) {
     dealloc_dir_handle(newhandle);

rights.c

@@ -63,30 +63,6 @@ static void rights_usage(void)
   fprintf(stdout, "               | Modify | File scan | Access Control\n");
 }
 
-static void rights_parent_path(char *dst, char *src, int max)
-{
-  char tmp[260];
-  char *p;
-
-  tool_upcopy(tmp, src, sizeof(tmp));
-
-  p = strrchr(tmp, '\\');
-  if (!p) p = strrchr(tmp, ':');
-
-  if (!p) {
-    dst[0] = '\0';
-    return;
-  }
-
-  if (*p == ':') {
-    p++;
-    *p = '\0';
-  } else {
-    *p = '\0';
-  }
-
-  strmaxcpy(dst, tmp, max - 1);
-}
 
 static void rights_ncp_path(char *dst, char *src, int max)
 {
@@ -184,7 +160,7 @@ static int rights_effective_mask(char *path, int is_dir, uint8 *mask)
   } else {
     char npath[260];
     rights_ncp_path(npath, path, sizeof(npath));
-    rights_parent_path(usepath, npath, sizeof(usepath));
+    tool_parent_path(usepath, npath, sizeof(usepath));
   }
 
   newhandle = alloc_temp_dir_handle(dhandle, usepath, 0, &eff);

tools.c

@@ -998,6 +998,37 @@ int tool_has_wildcards(char *path)
   return(0);
 }
 
+/*
+ * tool_parent_path
+ *
+ * Purpose:
+ *   Copies the parent directory part of a DOS/NetWare path.  The result is
+ *   uppercased and keeps a trailing volume colon for paths like SYS:FILE.TXT.
+ */
+void tool_parent_path(char *dst, char *src, int max)
+{
+  char tmp[260];
+  char *p;
+
+  tool_upcopy(tmp, src, sizeof(tmp));
+  p = strrchr(tmp, '\\');
+  if (!p) p = strrchr(tmp, ':');
+
+  if (!p) {
+    dst[0] = '\0';
+    return;
+  }
+
+  if (*p == ':') {
+    p++;
+    *p = '\0';
+  } else {
+    *p = '\0';
+  }
+
+  strmaxcpy(dst, tmp, max - 1);
+}
+
 /*
  * tool_parent_pattern
  *