const'ify our strtod() helper functions

The C library doesn't use const char pointers for legacy reasons (and
because you *can* modify the string the end pointer points to), but
let's do it in our internal implementation just because it's a nice
guarantee to have.

We actually used to have a non-const end pointer and replace a decimal
comma with a decimal dot, but that was because we didn't have the fancy
"allow commas" flags.  So by using our own strtod_flags() function, we
can now keep all the strings we parse read-only rather than modify them
as we parse them.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

dive.h

@@ -806,7 +806,7 @@ extern void remove_weightsystem(struct dive *dive, int idx);
 #define STRTOD_NO_DOT		0x02
 #define STRTOD_NO_COMMA		0x04
 #define STRTOD_NO_EXPONENT	0x08
-extern double strtod_flags(char *str, char **ptr, unsigned int flags);
+extern double strtod_flags(const char *str, const char **ptr, unsigned int flags);
 
 #define STRTOD_ASCII (STRTOD_NO_COMMA)
 

parse-xml.c

@@ -263,7 +263,7 @@ enum number_type {
 	FLOAT
 };
 
-static enum number_type parse_float(char *buffer, double *res, char **endp)
+static enum number_type parse_float(const char *buffer, double *res, const char **endp)
 {
 	double val;
 	static bool first_time = TRUE;
@@ -281,9 +281,8 @@ static enum number_type parse_float(char *buffer, double *res, char **endp)
 				fprintf(stderr, "Floating point value with decimal comma (%s)?\n", buffer);
 				first_time = FALSE;
 			}
-			/* Try again */
-			**endp = '.';
-			val = ascii_strtod(buffer, endp);
+			/* Try again in permissive mode*/
+			val = strtod_flags(buffer, endp, 0);
 		}
 	}
 
@@ -297,7 +296,7 @@ union int_or_float {
 
 static enum number_type integer_or_float(char *buffer, union int_or_float *res)
 {
-	char *end;
+	const char *end;
 	return parse_float(buffer, &res->fp, &end);
 }
 
@@ -459,7 +458,7 @@ static void percent(char *buffer, void *_fraction)
 {
 	fraction_t *fraction = _fraction;
 	double val;
-	char *end;
+	const char *end;
 
 	switch (parse_float(buffer, &val, &end)) {
 	case FLOAT:

qt-ui/models.cpp

@@ -464,9 +464,9 @@ void WeightModel::passInData(const QModelIndex& index, const QVariant& value)
 	}
 }
 
-weight_t string_to_weight(char *str)
+weight_t string_to_weight(const char *str)
 {
-	char *end;
+	const char *end;
 	double value = strtod_flags(str, &end, 0);
 	QString rest = QString(end).trimmed();
 	QString local_kg = WeightModel::tr("kg");

strtod.c

@@ -29,9 +29,10 @@
 #include <ctype.h>
 #include "dive.h"
 
-double strtod_flags(char *str, char **ptr, unsigned int flags)
+double strtod_flags(const char *str, const char **ptr, unsigned int flags)
 {
-	char *p = str, c, *ep;
+	char c;
+	const char *p = str, *ep;
 	double val = 0.0;
 	double decimal = 1.0;
 	int sign = 0, esign = 0;