scan_uint and scan_ushort will now abort if the result does not fit in

uint or ushort as opposed to ulong.

scan/scan_uint.c

@@ -1,8 +1,30 @@
 #include "scan.h"
 
+/* this is cut and paste from scan_ulong instead of calling scan_ulong
+ * because this way scan_uint can abort scanning when the number would
+ * not fit into an unsigned int (as opposed to not fitting in an
+ * unsigned long) */
+
 unsigned int scan_uint(const char* src,unsigned int* dest) {
-  unsigned long l;
-  register int len=scan_ulong(src,&l);
-  *dest=l;
-  return len;
+  if (sizeof(unsigned int) == sizeof(unsigned long)) {
+    /* a good optimizing compiler should remove the else clause when not
+     * needed */
+    return scan_ulong(src,(unsigned long*)dest);
+  } else {
+    register const char *tmp=src;
+    register unsigned int l=0;
+    register unsigned char c;
+    while ((c=*tmp-'0')<10) {
+      unsigned int n;
+      /* division is very slow on most architectures */
+      n=l<<3; if ((n>>3)!=l) break;
+      if (n+(l<<1) < n) break;
+      n+=l<<1;
+      if (n+c < n) break;
+      l=n+c;
+      ++tmp;
+    }
+    *dest=l;
+    return tmp-src;
+  }
 }

scan/scan_ushort.c

@@ -1,8 +1,30 @@
 #include "scan.h"
 
+/* this is cut and paste from scan_ulong instead of calling scan_ulong
+ * because this way scan_ushort can abort scanning when the number would
+ * not fit into an unsigned short (as opposed to not fitting in an
+ * unsigned long) */
+
 unsigned int scan_ushort(const char* src,unsigned short* dest) {
-  unsigned long l;
-  register int len=scan_ulong(src,&l);
-  *dest=l;
-  return len;
+  if (sizeof(unsigned short) == sizeof(unsigned int)) {
+    /* a good optimizing compiler should remove the else clause when not
+     * needed */
+    return scan_uint(src,(unsigned int*)dest);
+  } else {
+    register const char *tmp=src;
+    register unsigned short int l=0;
+    register unsigned char c;
+    while ((c=*tmp-'0')<10) {
+      unsigned short int n;
+      /* division is very slow on most architectures */
+      n=l<<3; if ((n>>3)!=l) break;
+      if (n+(l<<1) < n) break;
+      n+=l<<1;
+      if (n+c < n) break;
+      l=n+c;
+      ++tmp;
+    }
+    *dest=l;
+    return tmp-src;
+  }
 }