Index: runtime.c
===================================================================
--- runtime.c
+++ runtime.c
@@ -7304,20 +7304,19 @@
   if(C_immediatep(str) || C_header_bits(str) != C_STRING_TYPE)
     barf(C_BAD_ARGUMENT_TYPE_ERROR, "string->number", str);
 
   if((n = C_header_size(str)) == 0) {
   fail:
-    n = C_SCHEME_FALSE;
-    goto fini;
+    return C_SCHEME_FALSE;
   }
 
   if(n >= STRING_BUFFER_SIZE - 1) goto fail;
 
-  C_memcpy(sptr = buffer, C_c_string(str), n > (STRING_BUFFER_SIZE - 1) ? STRING_BUFFER_SIZE : n);
+  C_memcpy(sptr = buffer, C_c_string(str), n);
   buffer[ n ] = '\0';
 
-  while(*sptr == '#') {
+  if(*sptr == '#') {
     switch(C_tolower((int)*(++sptr))) {
     case 'b': if(radixpf) goto fail; else { radix = 2; radixpf = 1; } break;
     case 'o': if(radixpf) goto fail; else { radix = 8; radixpf = 1; } break;
     case 'd': if(radixpf) goto fail; else { radix = 10; radixpf = 1; } break;
     case 'x': if(radixpf) goto fail; else { radix = 16; radixpf = 1; } break;
@@ -7329,11 +7328,11 @@
     ++sptr;
   }
 
   /* Scan for embedded special characters and do basic sanity checking: */
   for(eptr = sptr, rptr = sptr; *eptr != '\0'; ++eptr) {
-    switch(C_tolower((int)*eptr)) {
+    switch(*eptr) {
     case '.':
       if(periodf || ratf || expf) goto fail;
 
       periodf = 1;
       break;
@@ -7352,15 +7351,15 @@
 
       sharpf = 0; /* Allow sharp signs in the denominator */
       ratf = 1;
       rptr = eptr+1;
       break;
-    case 'e':
-    case 'd':
-    case 'f':
-    case 'l':
-    case 's':
+    case 'e': case 'E':
+    case 'd': case 'D':
+    case 'f': case 'F':
+    case 'l': case 'L':
+    case 's': case 'S':
       /* Don't set exp flag if we see the "f" in "inf.0" (preceded by 'n') */
       /* Other failure modes are handled elsewhere. */
       if(radix == 10 && eptr > sptr && C_tolower((int)*(eptr-1)) != 'n') {
         if (ratf) goto fail;
 
@@ -7377,19 +7376,17 @@
   if (eptr == rptr) goto fail; /* Disallow "empty" numbers like "#x" and "1/" */
 
   /* check for rational representation: */
   if(rptr != sptr) {
     if (*(rptr) == '-' || *(rptr) == '+') {
-      n = C_SCHEME_FALSE;
-      goto fini;
+      return C_SCHEME_FALSE;
     }
     *(rptr-1) = '\0';
 
     switch(convert_string_to_number(sptr, radix, &n1, &fn1)) {
     case 0:
-      n = C_SCHEME_FALSE;
-      goto fini;
+      return C_SCHEME_FALSE;
 
     case 1:
       fn1 = (double)n1;
       break;
 
@@ -7421,11 +7418,10 @@
     if(exactpf && exactf) n = C_i_inexact_to_exact(n);
 
     break;
   }
 
- fini:
   return n;
 }
 
 
 /* only left for backwards-compatibility */
@@ -7505,11 +7501,11 @@
         return 0;
     }
 #endif
   }
 
-  if(C_strpbrk(str, "xX\0") != NULL) return 0;
+  if(C_strpbrk(str, "xX") != NULL) return 0;
 
   errno = 0;
   n = C_strtol(str, &eptr, radix);
 
   if(((n == LONG_MAX || n == LONG_MIN) && errno == ERANGE) || *eptr != '\0') {
@@ -7519,19 +7515,19 @@
     errno = 0;
     fn = C_strtod(str, &eptr2);
 
     if(fn == HUGE_VAL && errno == ERANGE) return 0;
     else if(eptr2 == str) return 0;
-    else if(*eptr2 == '\0' || (eptr != eptr2 && !C_strncmp(eptr2, ".0", C_strlen(eptr2)))) {
+    else if(*eptr2 == '\0' || (eptr != eptr2 && !C_strncmp(eptr2, ".0", len - (eptr2-str)))) {
       *flo = fn;
       return 2;
     }
 
     return 0;
   }
   else if((n & C_INT_SIGN_BIT) != ((n << 1) & C_INT_SIGN_BIT)) { /* doesn't fit into fixnum? */
-    if(*eptr == '\0' || !C_strncmp(eptr, ".0", C_strlen(eptr))) {
+    if(*eptr == '\0' || !C_strncmp(eptr, ".0", len - (eptr-str))) {
       *flo = (double)n;
       return 2;
     }
     else return 0;
   }