[gimp] plug-ins: TGA 16-bit RGB (without alpha bit) is also valid.

[Jehan Pagès <jehanp src gnome org>]

commit 8ea316667c8a3296bce2832b3986b58d0fdfc077
Author: Jehan <jehan girinstud io>
Date:   Wed Dec 20 13:26:26 2017 +0100

    plug-ins: TGA 16-bit RGB (without alpha bit) is also valid.
    
    According to some spec on the web, 16-bit RGB is also valid. In this
    case, the last bit is simply ignored (at least that's how it is
    implemented right now).

 plug-ins/common/file-tga.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/plug-ins/common/file-tga.c b/plug-ins/common/file-tga.c
index ad09679..6e768cc 100644
--- a/plug-ins/common/file-tga.c
+++ b/plug-ins/common/file-tga.c
@@ -568,7 +568,8 @@ load_image (const gchar  *filename,
              info.bpp != 24 && info.bpp != 32)      ||
             ((info.bpp == 15 || info.bpp == 24) &&
              info.alphaBits != 0)                   ||
-            (info.bpp == 16 && info.alphaBits != 1) ||
+            (info.bpp == 16 && info.alphaBits != 1 &&
+             info.alphaBits != 0)                   ||
             (info.bpp == 32 && info.alphaBits != 8))
           {
             g_message ("Unhandled sub-format in '%s' (type = %u, bpp = %u, alpha = %u)",