Avoid compiler warnings: "warning: deprecated conversion from string constant to 'char*\" and similar.

src/common/common.cpp

@@ -1347,7 +1347,7 @@ mxmsg(int level,
       va_list ap) {
   string new_fmt, output;
   bool nl;
-  char *prefix;
+  const char *prefix;
 
   fix_format(fmt, new_fmt);
 

src/common/mm_io.cpp

@@ -63,7 +63,7 @@ mm_file_io_c::mm_file_io_c(const string &path,
   file_name(path) {
 
   string local_path;
-  char *cmode;
+  const char *cmode;
   struct stat st;
 # if HAVE_POSIX_FADVISE
   int advise;

src/common/wavpack_common.cpp

@@ -26,7 +26,7 @@ const uint32_t sample_rates [] = {
 
 static void
 little_endian_to_native(void *data,
-                        char *format) {
+                        const char *format) {
   uint8_t *cp = (uint8_t *)data;
   uint32_t temp;
 

src/extract/xtr_avi.cpp

@@ -96,7 +96,7 @@ xtr_avi_c::handle_frame(memory_cptr &frame,
 
     nfr = irnd((double)duration / 1000000.0 * fps / 1000.0);
     for (k = 2; k <= nfr; k++)
-      AVI_write_frame(avi, "", 0, 0);
+      AVI_write_frame(avi, NULL, 0, 0);
   }
 }
 

src/info/matroska.xpm

@@ -1,5 +1,5 @@
 /* XPM */
-static char * matroska_xpm[] = {
+static const char * matroska_xpm[] = {
 "32 32 160 2",
 "  	c None",
 ". 	c #121212",

src/mmg/matroskalogo.xpm

@@ -1,5 +1,5 @@
 /* XPM */
-static char * matroskalogo_xpm[] = {
+static const char * matroskalogo_xpm[] = {
 "32 32 262 2",
 "  	c None",
 ". 	c #FFFFFF",

src/mmg/tab_input.cpp

@@ -216,7 +216,7 @@ tab_input::set_track_mode(mmg_track_t *t) {
 
 void
 tab_input::select_file(bool append) {
-  static struct { wxChar *title, *extensions; } file_types[] = {
+  static struct { const wxChar *title, *extensions; } file_types[] = {
     { wxT("A/52 (aka AC3)"), wxT("ac3") },
     { wxT("AAC (Advanced Audio Coding)"), wxT("aac m4a mp4") },
     { wxT("AVC/h.264 elementary streams"), wxT("264 avc h264 x264") },