safer fix for avahi_compat startup warning

CMakeLists.txt

@@ -13,7 +13,11 @@ include_directories(${X11_INCLUDE_DIR})
 # link_directories(${X11_LIBRARIES})
 endif (ZOOMFIX)
 
-add_definitions(-DAVAHI_COMPAT_NOWARN)
+
+if (NO_AVAHI_FIX)
+else()
+add_definitions(-DSUPPRESS_AVAHI_COMPAT_WARNING)
+endif(NO_AVAHI_FIX)
 
 add_subdirectory(lib/llhttp)
 add_subdirectory(lib/playfair)

README.md

@@ -154,6 +154,8 @@ name "uxplay" (note the difference in capitalization).
 
 9. The avahi_compat "nag" warning on startup is suppressed, by placing
 "AVAHI_COMPAT_NOWARN=1" into the runtime environment when uxplay starts.
+(This uses a call to putenv(), If for any reason you dont want this fix,
+ run cmake as "cmake -DNO_AVAHI_FIX=ON -DZOOMFIX=ON .. ").
 
 # Disclaimer
 

uxplay.cpp

@@ -196,10 +196,11 @@ int main (int argc, char *argv[]) {
     unsigned short display_size[2] = {0}, tcp[2] = {0}, udp[3] = {0};
     videoflip_t videoflip[2] = { NONE , NONE };
     
-#ifdef AVAHI_COMPAT_NOWARN
-    //suppress avahi_compat nag message
-    char avahi_compat_nowarn[] = "AVAHI_COMPAT_NOWARN==1";
-    putenv(avahi_compat_nowarn);
+#ifdef SUPPRESS_AVAHI_COMPAT_WARNING
+    // suppress avahi_compat nag message.  avahi emits a "nag" warning (once)
+    // if  getenv("AVAHI_COMPAT_NOWARN") returns null.
+    static char avahi_compat_nowarn[] = "AVAHI_COMPAT_NOWARN=1";
+    if (!getenv("AVAHI_COMPAT_NOWARN")) putenv(avahi_compat_nowarn);
 #endif
     
     // Parse arguments