* don't ever print sign for unsigned conversions

* don't break when right justifying a number past the end of the buffer
* handle zero precision and the value zero more correctly


git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@12413 ec53bebd-3082-4978-b11e-865c3cabbd6b

lib/roken/snprintf.c

@@ -41,6 +41,7 @@ RCSID("$Id$");
 #include <string.h>
 #include <ctype.h>
 #include <roken.h>
+#include <assert.h>
 
 enum format_flags {
     minus_flag     =  1,
@@ -123,14 +124,24 @@ typedef unsigned long u_longest;
 typedef long longest;
 #endif
 
-/*
- * is # supposed to do anything?
- */
 
+
+static int
+pad(struct snprintf_state *state, int width, char c)
+{
+    int len = 0;
+    while(width-- > 0){
+	(*state->append_char)(state,  c);
+	++len;
+    }
+    return len;
+}
+
+/* return true if we should use alternatve hex form */
 static int
 use_alternative (int flags, u_longest num, unsigned base)
 {
-  return flags & alternate_flag && (base == 16 || base == 8) && num != 0;
+    return (flags & alternate_flag) && base == 16 && num != 0;
 }
 
 static int
@@ -139,77 +150,108 @@ append_number(struct snprintf_state *state,
 	      int width, int prec, int flags, int minusp)
 {
     int len = 0;
-  int i;
     u_longest n = num;
+    char nstr[64]; /* enough for <192 bit octal integers */
+    int nstart, nlen;
+    char signchar;
 
     /* given precision, ignore zero flag */
     if(prec != -1)
 	flags &= ~zero_flag;
     else
 	prec = 1;
-  /* zero value with zero precision -> "" */
+
-  if(prec == 0 && n == 0)
+    /* format number as string */
-    return 0;
+    nstart = sizeof(nstr);
-  do{
+    nlen = 0;
-    (*state->append_char)(state, rep[n % base]);
+    nstr[--nstart] = '\0';
-    ++len;
+    do {
+	assert(nstart > 0);
+	nstr[--nstart] = rep[n % base];
+	++nlen;
 	n /= base;
     } while(n);
-  prec -= len;
+
-  /* pad with prec zeros */
+    /* zero value with zero precision should produce no digits */
-  while(prec-- > 0){
+    if(prec == 0 && num == 0) {
-    (*state->append_char)(state, '0');
+	nlen--;
-    ++len;
+	nstart++;
     }
-  /* add length of alternate prefix (added later) to len */
+
+    /* figure out what char to use for sign */
+    if(minusp)
+	signchar = '-';
+    else if((flags & plus_flag))
+	signchar = '+';
+    else if((flags & space_flag))
+	signchar = ' ';
+    else
+	signchar = '\0';
+    
+    if((flags & alternate_flag) && base == 8) {
+	/* if necessary, increase the precision to 
+	   make first digit a zero */
+
+	/* XXX C99 claims (regarding # and %o) that "if the value and
+           precision are both 0, a single 0 is printed", but there is
+           no such wording for %x. This would mean that %#.o would
+           output "0", but %#.x "". This does not make sense, and is
+           also not what other printf implementations are doing. */
+	
+	if(prec <= nlen && nstr[nstart] != '0' && nstr[nstart] != '\0')
+	    prec = nlen + 1;
+    }
+
+    /* possible formats:
+       pad | sign | alt | zero | digits
+       sign | alt | zero | digits | pad   minus_flag
+       sign | alt | zero | digits zero_flag */
+
+    /* if not right justifying or padding with zeros, we need to
+       compute the length of the rest of the string, and then pad with
+       spaces */
+    if(!(flags & (minus_flag | zero_flag))) {
+	if(prec > nlen)
+	    width -= prec;
+	else
+	    width -= nlen;
+	
 	if(use_alternative(flags, num, base))
-    len += base / 8;
+	    width -= 2;
-  /* pad with zeros */
+	
-  if(flags & zero_flag){
+	if(signchar != '\0')
-    width -= len;
-    if(minusp || (flags & space_flag) || (flags & plus_flag))
 	    width--;
-    while(width-- > 0){
+	
+	/* pad to width */
+	len += pad(state, width, ' ');
+    }
+    if(signchar != '\0') {
+	(*state->append_char)(state, signchar);
+	++len;
+    }
+    if(use_alternative(flags, num, base)) {
 	(*state->append_char)(state, '0');
-      len++;
-    }
-  }
-  /* add alternate prefix */
-  if(use_alternative(flags, num, base)){
-    if(base == 16)
 	(*state->append_char)(state, rep[10] + 23); /* XXX */
-    (*state->append_char)(state, '0');
+	len += 2;
     }
-  /* add sign */
+    if(flags & zero_flag) {
-  if(minusp){
+	/* pad to width with zeros */
-    (*state->append_char)(state, '-');
+	if(prec - nlen > width - len - nlen)
-    ++len;
+	    len += pad(state, prec - nlen, '0');
-  } else if(flags & plus_flag) {
+	else
-    (*state->append_char)(state, '+');
+	    len += pad(state, width - len - nlen, '0');
-    ++len;
+    } else
-  } else if(flags & space_flag) {
+	/* pad to prec with zeros */
-    (*state->append_char)(state, ' ');
+	len += pad(state, prec - nlen, '0');
+	
+    while(nstr[nstart] != '\0') {
+	(*state->append_char)(state, nstr[nstart++]);
 	++len;
     }
+	
     if(flags & minus_flag)
-    /* swap before padding with spaces */
+	len += pad(state, width - len, ' ');
-    for(i = 0; i < len / 2; i++){
+
-      char c = state->s[-i-1];
-      state->s[-i-1] = state->s[-len+i];
-      state->s[-len+i] = c;
-    }
-  width -= len;
-  while(width-- > 0){
-    (*state->append_char)(state,  ' ');
-    ++len;
-  }
-  if(!(flags & minus_flag))
-    /* swap after padding with spaces */
-    for(i = 0; i < len / 2; i++){
-      char c = state->s[-i-1];
-      state->s[-i-1] = state->s[-len+i];
-      state->s[-len+i] = c;
-    }
     return len;
 }
 
@@ -234,10 +276,8 @@ append_string (struct snprintf_state *state,
     else
 	width -= strlen((const char *)arg);
     if(!(flags & minus_flag))
-	while(width-- > 0) {
+	len += pad(state, width, ' ');
-	    (*state->append_char) (state, ' ');
+
-	    ++len;
-	}
     if (prec != -1) {
 	while (*arg && prec--) {
 	    (*state->append_char) (state, *arg++);
@@ -250,10 +290,7 @@ append_string (struct snprintf_state *state,
 	}
     }
     if(flags & minus_flag)
-	while(width-- > 0) {
+	len += pad(state, width, ' ');
-	    (*state->append_char) (state, ' ');
-	    ++len;
-	}
     return len;
 }
 
@@ -390,6 +427,9 @@ xyzprintf (struct snprintf_state *state, const char *char_format, va_list ap)
 		}
 	    }
 
+	    if(c != 'd' && c != 'i')
+		flags &= ~(plus_flag | space_flag);
+
 	    switch (c) {
 	    case 'c' :
 		append_char(state, va_arg(ap, int), width, flags);