This commit was manufactured by cvs2git to create tag 'RISC_OSLib-5_83-1'.

Sprout from master 2014-08-23 21:27:33 UTC Robert Sprowson <rsprowson@gitlab.riscosopen.org> 'Minor rlib cleanups'
Cherrypick from master 2011-10-28 14:23:50 UTC Ben Avison <bavison@gitlab.riscosopen.org> '  File handling improvements':
    c/scanf

c/scanf

@@ -635,22 +635,21 @@ static long int rd_string(FILE *p, va_list res, int flag, int field)
     return charcount;
 }
 
-/* Can "%[blah]" match a zero-length string? No                            */
-/* ISO9899 7.19.6.2 Matches a nonempty sequence of characters              */
+/* Ambiguity in Oct 86 ANSI draft: can "%[x]" match a zero-length string?  */
+/* p119 line 19 suggests no, p121 example suggests yes.  Treat as yes here */
 static long int rd_string_map(FILE *p, va_list res, int flag, int field,
-                              unsigned int charmap[])
+                              int charmap[])
 {   long int charcount = -1;                     /* allow for always ungetc */
     int ch; char *s = NULL;
     if (!(flag & NOSTORE)) s = va_arg(res, char *);
     ch = countgetc(p);
     if (ch == EOF) return CVTEOF;
-    while (field > 0 && ch != EOF && (charmap[ch/32] & (1uL<<(ch%32))) != 0)
+    while (field > 0 && ch != EOF && (charmap[ch/32] & (1<<(ch%32))) != 0)
     {   field--;
         if (!(flag & NOSTORE)) *s++ = ch;
         ch = countgetc(p);
     }
     __backspace(p);                               /* OK if ch == EOF         */
-    if (charcount == 0) return CVTFAIL;
     if (!(flag & NOSTORE)) *s = 0;
     return charcount;
 }
@@ -784,13 +783,12 @@ case '%':   {   int field = 0, flag = 0;
         case 'x':
         case 'X':   worked = rd_int(p, argv, flag | ALLOWSIGN, 16, field);
                     break;
-        case '[':   {   int negated = 0, i;
-                        unsigned int charmap[8];
+        case '[':   {   int negated = 0, i, charmap[8];
                         if ((fch = *fmt++) == '^') negated = 1, fch = *fmt++;
                         for (i=0; i<8; i++) charmap[i] = 0;
                         /* the 'do' next allows special treatment of %[]})] */
                         do { if (fch==0) return cnt;  /* %[... unterminated */
-                             charmap[fch/32] |= 1u<<(fch%32);
+                             charmap[fch/32] |= 1<<(fch%32);
                         } while ((fch = *fmt++) != ']');
                         if (negated) for (i=0; i<8; i++)
                             charmap[i] = ~charmap[i];