stdio: fix scanf bounds breaking strto*

Mostly an initialization problem. But I also optimized the check by
making the bound a maximal unsigned integer when there is no bound,
since __scanf_peek() is used a lot.

src/stdio/scanf/scan.c

@@ -6,12 +6,11 @@
 
 void __scanf_start(struct __scanf_input *in)
 {
-
     if(in->fp)
         in->buffer = fgetc(in->fp);
     else {
         in->buffer = (*in->str ? *in->str : EOF);
-        in->str += (in->buffer != 0);
+        in->str += (in->buffer != EOF);
     }
 }
 
@@ -286,7 +285,7 @@ int __scanf(
 					// we need to assign the read char to the corresponding pointer 
 					if (!skip) {
 						char *c = (char *) va_arg( *args, char* );
-						if (in->readmaxlength==-1) {
+						if (in->readmaxlength==(unsigned int)-1) {
 							for(;;) {
 								temp = __scanf_peek( in );
 								if (temp==EOF) return EOF;
@@ -305,7 +304,7 @@ int __scanf(
 							}
 						}
 						else {
-							for(int u=0; u<in->readmaxlength; u++) {
+							for(unsigned int u=0; u<in->readmaxlength; u++) {
 								temp = __scanf_peek( in );
 								if (temp==EOF) return EOF;
 								else if (__is_allowed( temp ))	{
@@ -332,7 +331,7 @@ int __scanf(
 
 					else
 					{
-						if (in->readmaxlength==-1) {
+						if (in->readmaxlength==(unsigned int)-1) {
 							for(;;)	{
 								temp = __scanf_peek( in );
 								if (temp==EOF) return EOF;
@@ -345,7 +344,7 @@ int __scanf(
 							}
 						}
 						else {
-							for(int u=0; u<in->readmaxlength; u++) {
+							for(unsigned int u=0; u<in->readmaxlength; u++) {
 								temp = __scanf_peek( in );
 								if (temp==EOF) return EOF;
 								else if (__is_allowed( temp )) __scanf_in( in );
@@ -546,13 +545,13 @@ int __scanf(
 					char temp;
 					if (!skip) {
 						char *c = (char *) va_arg( *args, char* );
-						if (in->readmaxlength==-1) {
+						if (in->readmaxlength==(unsigned int)-1) {
 							temp = __scanf_peek( in );
 							if (temp==EOF) return EOF;
 							else *c = __scanf_in( in );
 						}
 						else {
-							for( int u = 0; u < in->readmaxlength; u++ ) {
+							for( unsigned int u = 0; u < in->readmaxlength; u++ ) {
 								temp = __scanf_peek( in );
 								if (temp==EOF) return EOF;
 								else *c++ = __scanf_in( in );
@@ -560,7 +559,7 @@ int __scanf(
 						}
 					}
 					else {
-						if (in->readmaxlength==-1) {
+						if (in->readmaxlength==(unsigned int)-1) {
 							temp = __scanf_peek( in );
 							if (temp==EOF) return EOF;
 							else {
@@ -569,7 +568,7 @@ int __scanf(
 							} 
 						}
 						else {
-							for( int u = 0; u < in->readmaxlength; u++ ) {
+							for( unsigned int u = 0; u < in->readmaxlength; u++ ) {
 								temp = __scanf_peek( in );
 								if (temp==EOF) return EOF;
 								else __scanf_in( in );
@@ -590,7 +589,7 @@ int __scanf(
 					__purge_space( in );
 					if (!skip)	{
 						char *c = (char *) va_arg( *args, char* );
-						if (in->readmaxlength==-1) {
+						if (in->readmaxlength==(unsigned int)-1) {
 							loopstring:
 							temp = __scanf_peek( in );
 							if (temp==EOF && curstrlength==0) return validrets;
@@ -605,7 +604,7 @@ int __scanf(
 							}
 						}
 						else {
-							for( int u = 0; u < in->readmaxlength; u++ ) {
+							for( unsigned int u = 0; u < in->readmaxlength; u++ ) {
 								temp = __scanf_peek( in );					
 								if (temp==EOF && curstrlength==0) return validrets;
 								if (isspace(temp) || ( (temp==EOF && curstrlength!=0) )) {
@@ -620,7 +619,7 @@ int __scanf(
 						}
 					}
 					else {
-						if (in->readmaxlength==-1) {
+						if (in->readmaxlength==(unsigned int)-1) {
 							loopstringskip:
 							temp = __scanf_peek( in );
 							if (temp==EOF && curstrlength==0) return validrets;
@@ -632,7 +631,7 @@ int __scanf(
 							}
 						}
 						else {
-							for( int u = 0; u < in->readmaxlength; u++ ) {
+							for( unsigned int u = 0; u < in->readmaxlength; u++ ) {
 								temp = __scanf_peek( in );							
 								if (temp==EOF && curstrlength==0) return validrets;
 								if (isspace(temp) || ( (temp==EOF && curstrlength!=0) )) goto loopstringendskip;

src/stdio/stdio_p.h

@@ -19,7 +19,7 @@ struct __scanf_input {
 	FILE *fp;
 
 	// max char to read from the input stream as per user length modifier
-	int readmaxlength;
+	unsigned int readmaxlength;
 	int currentlength;
 
 	// total number of char read so far in the current call of a XYscanf() function (to return a %n when required)
@@ -55,9 +55,8 @@ static inline int __scanf_in(struct __scanf_input *__in)
 /* Peek the next byte without advancing. */
 static inline int __scanf_peek(struct __scanf_input *__in)
 {
-	if (__in->readmaxlength==-1 || __in->currentlength<__in->readmaxlength )
+	return ((unsigned)__in->currentlength < __in->readmaxlength)
-		return __in->buffer;
+		? __in->buffer : EOF;
-	else return 0;
 }
 
 /* Close the input by unsending the buffer once finished. */

src/stdlib/strtod.c

@@ -7,7 +7,7 @@ double strtod(char const * restrict ptr, char ** restrict endptr)
 	if(endptr)
 		*endptr = (char *)ptr;
 
-	struct __scanf_input in = { .str = ptr, .fp = NULL };
+	struct __scanf_input in = { .str = ptr, .fp = NULL, .readmaxlength = -1 };
 	__scanf_start(&in);
 	int err = __strto_fp(&in, &d, NULL, NULL);
 	__scanf_end(&in);

src/stdlib/strtof.c

@@ -7,7 +7,7 @@ float strtof(char const * restrict ptr, char ** restrict endptr)
 	if(endptr)
 		*endptr = (char *)ptr;
 
-	struct __scanf_input in = { .str = ptr, .fp = NULL };
+	struct __scanf_input in = { .str = ptr, .fp = NULL, .readmaxlength = -1 };
 	__scanf_start(&in);
 	int err = __strto_fp(&in, NULL, &f, NULL);
 	__scanf_end(&in);

src/stdlib/strtol.c

@@ -7,7 +7,13 @@ long int strtol(char const * restrict ptr, char ** restrict endptr, int base)
 	if(endptr)
 		*endptr = (char *)ptr;
 
-	struct __scanf_input in = { .str = ptr, .fp = NULL };
+	struct __scanf_input in = {
+		.str = ptr,
+		.fp = NULL,
+		.readmaxlength = -1,
+		.currentlength = 0,
+		.readsofar = 0,
+	};
 	__scanf_start(&in);
 	int err = __strto_int(&in, base, &n, NULL, false);
 	__scanf_end(&in);

src/stdlib/strtold.c

@@ -7,7 +7,7 @@ long double strtold(char const * restrict ptr, char ** restrict endptr)
 	if(endptr)
 		*endptr = (char *)ptr;
 
-	struct __scanf_input in = { .str = ptr, .fp = NULL };
+	struct __scanf_input in = { .str = ptr, .fp = NULL, .readmaxlength = -1 };
 	__scanf_start(&in);
 	int err = __strto_fp(&in, NULL, NULL, &ld);
 	__scanf_end(&in);

src/stdlib/strtoll.c

@@ -8,7 +8,7 @@ long long int strtoll(char const * restrict ptr, char ** restrict endptr,
 	if(endptr)
 		*endptr = (char *)ptr;
 
-	struct __scanf_input in = { .str = ptr, .fp = NULL };
+	struct __scanf_input in = { .str = ptr, .fp = NULL, .readmaxlength = -1 };
 	__scanf_start(&in);
 	int err = __strto_int(&in, base, NULL, &n, false);
 	__scanf_end(&in);

src/stdlib/strtoul.c

@@ -8,7 +8,7 @@ unsigned long int strtoul(char const * restrict ptr, char ** restrict endptr,
 	if(endptr)
 		*endptr = (char *)ptr;
 
-	struct __scanf_input in = { .str = ptr, .fp = NULL };
+	struct __scanf_input in = { .str = ptr, .fp = NULL, .readmaxlength = -1 };
 	__scanf_start(&in);
 	int err = __strto_int(&in, base, (long *)&n, NULL, true);
 	__scanf_end(&in);

src/stdlib/strtoull.c

@@ -8,7 +8,7 @@ unsigned long long int strtoull(char const * restrict ptr,
 	if(endptr)
 		*endptr = (char *)ptr;
 
-	struct __scanf_input in = { .str = ptr, .fp = NULL };
+	struct __scanf_input in = { .str = ptr, .fp = NULL, .readmaxlength = -1 };
 	__scanf_start(&in);
 	int err = __strto_int(&in, base, NULL, (long long *)&n, true);
 	__scanf_end(&in);