Resolve "Write MKV tags without mkvpropedit as a dependency for the AppImage"

Closes #83 (closed)

inc/lektor/common.h

@@ -49,7 +49,12 @@
         LOG_DEBUG("DEBUG", "%s", msg);  \
         goto label;                     \
     }
+#define FAIL_IF(cond, ...) {            \
+    if (cond) {                         \
+        LOG_FATAL(__VA_ARGS__);         \
+    }}
 
+#define FAIL_UNLESS(cond, ...)          FAIL_IF(!(cond), __VA_ARGS__)
 #define GOTO_UNLESS(cond, msg, label)   GOTO_IF(!(cond), msg, label)
 #define RETURN_UNLESS(cond, msg, ret)   RETURN_IF(!(cond), msg, ret)
 #define NOTHING                         /* Usefull to return nothing in previous macros */
@@ -124,10 +129,10 @@ void __lkt_log(enum log_level, const char *section, const char *func, const char
 #define LKT_MESSAGE_MAX             2048
 #define LKT_DEFAULT_LIST_SIZE       10
 
-#define LKT_BACKLOG         32
-#define COMMAND_LIST_MAX    64
-#define BUFFER_OUT_MAX      16
-#define MPD_VERSION         "0.21.16"
+#define LKT_BACKLOG                 32
+#define COMMAND_LIST_MAX            64
+#define BUFFER_OUT_MAX              16
+#define MPD_VERSION                 "0.21.16"
 
 typedef volatile enum {
     MPD_IDLE_NONE               = 0,