[PATCH] cmd: Allow starting native executables

[Fabian Maurer]

Note that this is obviously different from what windows cmd
does, but Wine has a different situation.
Running native binaries without 'start' is pretty useful, IMHO.

We check for a magic signature to avoid regressions in case
there is a file without the extension that's not a native
executable.

Signed-off-by: Fabian Maurer <dark.shadow4 at web.de>
---
 programs/cmd/wcmdmain.c | 33 ++++++++++++++++++++++++++++-----
 1 file changed, 28 insertions(+), 5 deletions(-)

diff --git a/programs/cmd/wcmdmain.c b/programs/cmd/wcmdmain.c
index 637c0e94bd..26910ee4c8 100644
--- a/programs/cmd/wcmdmain.c
+++ b/programs/cmd/wcmdmain.c
@@ -1009,6 +1009,29 @@ static void init_msvcrt_io_block(STARTUPINFOW* st)
     }
 }

+static BOOL is_native_executable(WCHAR *path)
+{
+    HANDLE file;
+    char buffer[4];
+    static const char magic_elf[] = {0x7f, 'E', 'L', 'F'};
+    DWORD bytes_read;
+
+    file = CreateFileW(path, GENERIC_READ, 0, NULL, OPEN_EXISTING, 0, NULL);
+    ReadFile(file, buffer, ARRAY_SIZE(buffer), &bytes_read, NULL);
+    CloseHandle(file);
+
+    if (bytes_read < ARRAY_SIZE(buffer))
+        return FALSE;
+
+    if (memcmp(buffer, magic_elf, 4) == 0)
+        return TRUE;
+
+    if (memcmp(buffer, "#!/", 3) == 0)
+        return TRUE;
+
+    return FALSE;
+}
+
 /******************************************************************************
  * WCMD_run_program
  *
@@ -1141,11 +1164,11 @@ void WCMD_run_program (WCHAR *command, BOOL called)
     strcatW(thisDir, stemofsearch);
     pos = &thisDir[strlenW(thisDir)]; /* Pos = end of name */

-    /* 1. If extension supplied, see if that file exists */
-    if (extensionsupplied) {
-      if (GetFileAttributesW(thisDir) != INVALID_FILE_ATTRIBUTES) {
-        found = TRUE;
-      }
+    /* 1. If extension supplied, see if that file exists - also check if we got a path to a native executable */
+    if (GetFileAttributesW(thisDir) != INVALID_FILE_ATTRIBUTES) {
+        if (extensionsupplied || is_native_executable(thisDir)) {
+            found = TRUE;
+        }
     }

     /* 2. Any .* matches? */
--
2.21.0