shlwapi: Fix UrlCombineW for absolute URLs without slashes.

dlls/shlwapi/tests/path.c

@@ -205,6 +205,10 @@ const TEST_URL_COMBINE TEST_COMBINE[] = {
     {"xxx:@MSITStore:file.chm/file.html", "dir/file", 0, S_OK, "xxx:dir/file"},
     {"mk:@MSITStore:file.chm::/file.html", "/dir/file", 0, S_OK, "mk:@MSITStore:file.chm::/dir/file"},
     {"mk:@MSITStore:file.chm::/file.html", "mk:@MSITStore:file.chm::/dir/file", 0, S_OK, "mk:@MSITStore:file.chm::/dir/file"},
+    {"foo:today", "foo:calendar", 0, S_OK, "foo:calendar"},
+    {"foo:today", "bar:calendar", 0, S_OK, "bar:calendar"},
+    {"foo:/today", "foo:calendar", 0, S_OK, "foo:/calendar"},
+    {"foo:/today/", "foo:calendar", 0, S_OK, "foo:/today/calendar"},
 };
 
 struct {

dlls/shlwapi/url.c

@@ -736,8 +736,9 @@ HRESULT WINAPI UrlCombineW(LPCWSTR pszBase, LPCWSTR pszRelative,
 		process_case = 4;
 		break;
 	    }
-	    /* case where scheme is followed by document path */
-	    process_case = 5;
+            /* replace either just location if base's location starts with a
+             * slash or otherwise everything */
+            process_case = (*base.pszSuffix == '/') ? 5 : 1;
 	    break;
 	}
         if ((*relative.pszSuffix == '/') && (*(relative.pszSuffix+1) == '/')) {