remove new compiler warnings from gcc 7

ent.c

@@ -8,6 +8,7 @@
 #include "scan/scan_ulong.c"
 #include "scan/scan_ulongn.c"
 #include "fmt/fmt_utf8.c"
+#include "fmt/fmt_tohex.c"
 #include "fmt/fmt_escapecharc.c"
 
 char tmp[20];

scan/scan_double.c

@@ -11,7 +11,7 @@ size_t scan_double(const char *in, double *dest) {
   register const char *c=in;
   char neg=0;
   switch (*c) {
-  case '-': neg=1;
+  case '-': neg=1; /* fall through */
   case '+': c++; break;
   default: break;
   }
@@ -31,7 +31,7 @@ size_t scan_double(const char *in, double *dest) {
     char neg=0;
     if (c[1]<'0') {
       switch (*c) {
-      case '-': neg=1;
+      case '-': neg=1; /* fall through */
       case '+': c++; break;
       default:
 	d=0;

scan/scan_int.c

@@ -10,7 +10,7 @@ size_t scan_int(const char* src,int* dest) {
   int ok;
   tmp=src; l=0; ok=0; neg=0;
   switch (*tmp) {
-  case '-': neg=1;
+  case '-': neg=1; /* fall through */
   case '+': ++tmp;
   }
   while ((c=(unsigned char)(*tmp-'0'))<10) {

scan/scan_longn.c

@@ -11,7 +11,7 @@ size_t scan_longn(const char *src,size_t n,long *dest) {
   if (!n--) return 0;
   tmp=src; l=0; ok=0; neg=0;
   switch (*tmp) {
-  case '-': neg=1;
+  case '-': neg=1; /* fall through */
   case '+': ++tmp;
   }
   while (n-->0 && (c=(unsigned char)(*tmp-'0'))<10) {

scan/scan_plusminus.c

@@ -3,7 +3,7 @@
 size_t scan_plusminus(const char *src,signed int *dest) {
   *dest=1;
   switch (*src) {
-  case '-': *dest=-1;
+  case '-': *dest=-1; /* fall through */
   case '+': return 1; break;
   }
   return 0;

scan/scan_short.c

@@ -10,7 +10,7 @@ size_t scan_short(const char* src,short* dest) {
   int ok;
   tmp=src; l=0; ok=neg=0;
   switch (*tmp) {
-  case '-': neg=1;
+  case '-': neg=1; /* fall through */
   case '+': ++tmp;
   }
   while ((c=(unsigned char)(*tmp-'0'))<10) {

t.c

@@ -126,6 +126,7 @@ int main(int argc,char* argv[]) {
   (void)writecb;
   (void)argc;
   (void)argv;
+  (void)c;
   assert(fmt_jsonescape(buf,"foo\nbar\\",8)==10 && byte_equal(buf,10,"foo\\nbar\\\\"));
   memset(buf,0,sizeof(buf));
   assert(scan_jsonescape("foo\\u000abar\\\\",buf,&l)==14 && l==8 && byte_equal(buf,8,"foo\nbar\\"));

textcode/fmt_yenc.c

@@ -16,6 +16,7 @@ size_t fmt_yenc(char* dest,const char* src,size_t len) {
       goto dontescape;
     case 'F':	/* escape "^From " */
       if (s[i+1]+42!='r' || s[i+2]+42!='o' || s[i+3]+42!='m' || s[i+4]+42!=' ') goto dontescape;
+      /* fall through */
     case '.':	/* dot at start of line needs to be escaped */
       if (!linelen) goto dontescape;
       /* fall through */