file: try ismp4() before ismp3()

It is possible to find the mp3 sync word near the start of an mp4
file.  As such, file(1) could incorrectly identify some mp4s as mp3s.

diff --git a/sys/src/cmd/file.c b/sys/src/cmd/file.c
index 11577b3af784b01863f87f5c97bc5728ffc57529..bd9d1afb5b492146277b6c53411a34177dbc2026 100644 (file)
--- a/sys/src/cmd/file.c
+++ b/sys/src/cmd/file.c
@@ -201,8 +201,8 @@ int (*call[])(void) =
        isicocur,               /* windows icon or cursor file */
        isface,         /* ascii face file */
        istga,
-       ismp3,
        ismp4,
+       ismp3,
 
        /* last resorts */
        ismung,         /* entropy compressed/encrypted */