ncpalette_get: can't return -1 on uint32_t erp

doc/man/man3/notcurses_palette.3.md

@@ -27,7 +27,7 @@ typedef struct ncpalette {
 
 **int ncpalette_set(ncpalette* ***p***, int ***idx***, unsigned ***rgb***);**
 
-**uint32_t ncpalette_get(const ncpalette* ***p***, int ***idx***);**
+**int ncpalette_get(const ncpalette* ***p***, int ***idx***, uint32_t* ***palent***);**
 
 **int ncpalette_get_rgb8(const ncpalette* ***p***, int ***idx***, int* restrict ***r***, int* restrict ***g***, int* restrict ***b***);**
 

include/notcurses/notcurses.h

@@ -1550,12 +1550,13 @@ ncpalette_set(ncpalette* p, int idx, unsigned rgb){
   return ncchannel_set(&p->chans[idx], rgb);
 }
 
-static inline uint32_t
-ncpalette_get(const ncpalette* p, int idx){
+static inline int
+ncpalette_get(const ncpalette* p, int idx, uint32_t* palent){
   if(idx < 0 || (size_t)idx > sizeof(p->chans) / sizeof(*p->chans)){
     return -1;
   }
-  return ncchannel_rgb(p->chans[idx]);
+  *palent = ncchannel_rgb(p->chans[idx]);
+  return 0;
 }
 
 static inline int