win32: more efficient tests for executables

file_is_executable() calls access(2) and stat(2); in this case our
WIN32 implementation also calls stat(2).  Avoid this unnecessary
duplication by copying the required test from the WIN32 access(2).

In find_executable() it's possible to avoid calling file_is_executable()
if add_win32_extension() returns TRUE as the latter will already have
verified that the file is executable.

Replace a call to file_is_executable() in the tab completion code
with the equivalent tests, avoiding (up to) two calls to stat(2).

These changes don't affect the size of the binary and should be
faster.

1 files changed, 2 insertions, 2 deletions

diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index e7de32250..f17c9a215 100644
--- a/libbb/lineedit.c
+++ b/libbb/lineedit.c
@@ -958,8 +958,8 @@ static NOINLINE unsigned complete_cmd_dir_file(const char *command, int type)
                                 goto cont; /* hmm, remove in progress? */
 
 # if ENABLE_PLATFORM_MINGW32
-                        if (type == FIND_EXE_ONLY && !S_ISDIR(st.st_mode) &&
-                                        !file_is_executable(found))
+                        if (type == FIND_EXE_ONLY && S_ISREG(st.st_mode) &&
+                                        !(st.st_mode & S_IXUSR))
                                 goto cont;
 # endif