From df49986fab4fbae49c44d9c1ea69dadaf4dff74c Mon Sep 17 00:00:00 2001
From: Bill Kendrick <nbs@sonic.net>
Date: Thu, 12 Sep 2019 20:27:03 -0700
Subject: [PATCH] Add a FALL_THROUGH macro to compiler.h

Older gcc's don't support `__attribute__ ((fallthrough))`
(see https://sourceforge.net/u/begasus/tuxpaint/ci/e5c3cdfcf5e16a9b0fc3e7766bfea1d9c326b3ae/
"Haiku Fixes" by Luc), so adding a new macro to compiler.h
that is defined as "((void)0)" on older compilers.
---
 src/compiler.h | 14 ++++++++++++--
 src/im.c       | 19 +++++++++----------
 2 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/src/compiler.h b/src/compiler.h
index 5afeec307..82efd7a9c 100644
--- a/src/compiler.h
+++ b/src/compiler.h
@@ -5,7 +5,7 @@
   for Tux Paint
 
   Mostly by Albert Cahalan <albert@users.sf.net>
-  Copyright (c) 2002-2006
+  Copyright (c) 2002-2019
 
   http://www.newbreedsoftware.com/tuxpaint/
 
@@ -24,7 +24,7 @@
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   (See COPYING.txt)
 
-  June 14, 2002 - December 30, 2017
+  June 14, 2002 - September 12, 2019
   $Id$
 */
 
@@ -127,3 +127,13 @@
 #undef CLOCK_ASM
 #define CLOCK_ASM(x) x=42
 #endif
+
+/* h/t https://tutel.me/c/programming/questions/45349079/how+to+use+__attribute__fallthrough+correctly+in+gcc */
+#ifndef FALLTHROUGH
+#if defined(__GNUC__) && __GNUC__ >= 7
+ #define FALL_THROUGH __attribute__ ((fallthrough))
+#else
+ #define FALL_THROUGH ((void)0)
+#endif /* __GNUC__ >= 7 */
+#endif
+
diff --git a/src/im.c b/src/im.c
index 138cfad4f..ac7d5862b 100644
--- a/src/im.c
+++ b/src/im.c
@@ -45,7 +45,6 @@
 #include "im.h"
 
 
-
 /* ***************************************************************************
 * I18N GETTEXT
 */
@@ -905,12 +904,12 @@ static int im_event_zh_tw(IM_DATA * im, SDL_keysym ks)
 
     case IM_REQ_FREE:          /* Free allocated resources */
       charmap_free(&cm);
-      // // __attribute__ ((fallthrough)); /* go onto full reset */
+      FALL_THROUGH; /* go onto full reset */
 
     case IM_REQ_RESET_FULL:    /* Full reset */
       cm.section = SEC_ENGLISH;
       im->tip_text = im_tip_text[IM_TIP_ENGLISH];
-      // __attribute__ ((fallthrough)); /* go onto soft reset */
+      FALL_THROUGH; /* go onto soft reset */
 
     case IM_REQ_RESET_SOFT:    /* Soft reset */
       im->s[0] = L'\0';
@@ -1124,12 +1123,12 @@ static int im_event_th(IM_DATA * im, SDL_keysym ks)
 
     case IM_REQ_FREE:          /* Free allocated resources */
       charmap_free(&cm);
-      // __attribute__ ((fallthrough)); /* go onto full reset */
+      FALL_THROUGH; /* go onto full reset */
 
     case IM_REQ_RESET_FULL:    /* Full reset */
       cm.section = SEC_ENGLISH;
       im->tip_text = im_tip_text[IM_TIP_ENGLISH];
-      // __attribute__ ((fallthrough)); /* go onto soft reset */
+      FALL_THROUGH; /* go onto soft reset */
 
     case IM_REQ_RESET_SOFT:    /* Soft reset */
       im->s[0] = L'\0';
@@ -1343,12 +1342,12 @@ static int im_event_ja(IM_DATA * im, SDL_keysym ks)
 
     case IM_REQ_FREE:          /* Free allocated resources */
       charmap_free(&cm);
-      // __attribute__ ((fallthrough)); /* go onto full reset */
+      FALL_THROUGH; /* go onto full reset */
 
     case IM_REQ_RESET_FULL:    /* Full reset */
       cm.section = SEC_ENGLISH;
       im->tip_text = im_tip_text[IM_TIP_ENGLISH];
-      // __attribute__ ((fallthrough)); /* go onto soft reset */
+      FALL_THROUGH; /* go onto soft reset */
 
     case IM_REQ_RESET_SOFT:    /* Soft reset */
       im->s[0] = L'\0';
@@ -1590,12 +1589,12 @@ static int im_event_ko(IM_DATA * im, SDL_keysym ks)
 
     case IM_REQ_FREE:          /* Free allocated resources */
       charmap_free(&cm);
-      // __attribute__ ((fallthrough)); /* go onto full reset */
+      FALL_THROUGH; /* go onto full reset */
 
     case IM_REQ_RESET_FULL:    /* Full reset */
       cm.section = SEC_ENGLISH;
       im->tip_text = im_tip_text[IM_TIP_ENGLISH];
-      // __attribute__ ((fallthrough)); /* go onto soft reset */
+      FALL_THROUGH; /* go onto soft reset */
 
     case IM_REQ_RESET_SOFT:    /* Soft reset */
       im->s[0] = L'\0';
@@ -1681,7 +1680,7 @@ static int im_event_ko(IM_DATA * im, SDL_keysym ks)
             im->redraw--;
           ks.unicode = L'\0';
         }
-      // __attribute__ ((fallthrough)); /* continue processing: */
+      FALL_THROUGH; /* continue processing: */
 
       /* Actual character processing */
     default: