engine: common: add printf-like version of Info_SetValueForKey function.

engine/common/common.h

@@ -818,6 +818,7 @@ const char *Info_ValueForKey( const char *s, const char *key );
 void Info_RemovePrefixedKeys( char *start, char prefix );
 qboolean Info_RemoveKey( char *s, const char *key );
 qboolean Info_SetValueForKey( char *s, const char *key, const char *value, int maxsize );
+qboolean Info_SetValueForKeyf( char *s, const char *key, int maxsize, const char *format, ... ) _format( 4 );
 qboolean Info_SetValueForStarKey( char *s, const char *key, const char *value, int maxsize );
 qboolean Info_IsValid( const char *s );
 void Info_WriteVars( file_t *f );

engine/common/infostring.c

@@ -496,3 +496,16 @@ qboolean Info_SetValueForKey( char *s, const char *key, const char *value, int m
 
 	return Info_SetValueForStarKey( s, key, value, maxsize );
 }
+
+qboolean Info_SetValueForKeyf( char *s, const char *key, int maxsize, const char *format, ... )
+{
+	char value[MAX_VA_STRING];
+	va_list args;
+
+	va_start( args, format );
+	Q_vsnprintf( value, sizeof( value ), format, args );
+	va_end( args );
+
+	return Info_SetValueForKey( s, key, value, maxsize );
+}
+