# HG changeset patch
# User Matti Hamalainen <ccr@tnsp.org>
# Date 1529855595 -10800
# Node ID 1e8f60ce21d185f67a907a79b5cc47cd042eea38
# Parent  1067df067f284e3628cf61f3d0edc391a4e18f94
Add check for writability in output format option -f

diff -r 1067df067f28 -r 1e8f60ce21d1 tools/gfxconv.c
--- a/tools/gfxconv.c	Sun Jun 24 18:45:33 2018 +0300
+++ b/tools/gfxconv.c	Sun Jun 24 18:53:15 2018 +0300
@@ -585,7 +585,7 @@
                 dmGetConvFormat(optInFormat, optForcedInSubFormat, &fmt);
                 if ((fmt.flags & DM_FMT_RD) == 0)
                 {
-                    dmErrorMsg("Invalid input format '%s'.\n",
+                    dmErrorMsg("Invalid input format '%s', does not support reading.\n",
                         fmt.name);
                     return FALSE;
                 }
@@ -605,8 +605,20 @@
             break;
 
         case 5:
-            if (!dmParseFormatOption("output", "Output", optArg, &optOutFormat, &optOutSubFormat))
-                return FALSE;
+            {
+                DMConvFormat fmt;
+
+                if (!dmParseFormatOption("output", "Output", optArg, &optOutFormat, &optOutSubFormat))
+                    return FALSE;
+
+                dmGetConvFormat(optOutFormat, optOutSubFormat, &fmt);
+                if ((fmt.flags & DM_FMT_WR) == 0)
+                {
+                    dmErrorMsg("Invalid output format '%s', does not support writing.\n",
+                        fmt.name);
+                    return FALSE;
+                }
+            }
             break;
 
         case 6: