Modify locale code to defend against possibility that it was compiled

with an -fsigned-char/-funsigned-char setting opposite to that of libc,
thus breaking the convention that 'undefined' values returned by
localeconv() are represented by CHAR_MAX.  It is sheer stupidity that
gcc even has such a switch --- it's just as bad as the structure-packing
control switches offered by the more brain-dead PC compilers --- and
as for the behavior of Linux distribution vendors who set RPM_OPT_FLAGS
differently from the way they built libc, well, words fail me...

diff --git a/src/backend/utils/adt/cash.c b/src/backend/utils/adt/cash.c
index d924bf3..696559a 100644 (file)
--- a/src/backend/utils/adt/cash.c
+++ b/src/backend/utils/adt/cash.c
@@ -9,7 +9,7 @@
  * workings can be found in the book "Software Solutions in C" by
  * Dale Schumacher, Academic Press, ISBN: 0-12-632360-7.
  *
- * $Header: /cvsroot/pgsql/src/backend/utils/adt/cash.c,v 1.45 2000/08/03 16:34:22 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/utils/adt/cash.c,v 1.46 2000/11/18 03:55:51 tgl Exp $
  */
 
 #include <limits.h>
@@ -91,9 +91,19 @@ cash_in(PG_FUNCTION_ARGS)
        if (lconvert == NULL)
                lconvert = localeconv();
 
-       /* frac_digits in the C locale seems to return CHAR_MAX */
-       /* best guess is 2 in this case I think */
-       fpoint = ((lconvert->frac_digits != (char)CHAR_MAX) ? lconvert->frac_digits : 2); /* int_frac_digits? */
+       /*
+        * frac_digits will be CHAR_MAX in some locales, notably C.  However,
+        * just testing for == CHAR_MAX is risky, because of compilers like
+        * gcc that "helpfully" let you alter the platform-standard definition
+        * of whether char is signed or not.  If we are so unfortunate as to
+        * get compiled with a nonstandard -fsigned-char or -funsigned-char
+        * switch, then our idea of CHAR_MAX will not agree with libc's.
+        * The safest course is not to test for CHAR_MAX at all, but to impose
+        * a range check for plausible frac_digits values.
+        */
+       fpoint = lconvert->frac_digits;
+       if (fpoint < 0 || fpoint > 10)
+               fpoint = 2;                             /* best guess in this case, I think */
 
        dsymbol = ((*lconvert->mon_decimal_point != '\0') ? *lconvert->mon_decimal_point : '.');
        ssymbol = ((*lconvert->mon_thousands_sep != '\0') ? *lconvert->mon_thousands_sep : ',');
@@ -225,9 +235,9 @@ cash_out(PG_FUNCTION_ARGS)
        int                     count = LAST_DIGIT;
        int                     point_pos;
        int                     comma_position = 0;
-       char            mon_group,
-                               comma,
-                               points;
+       int                     points,
+                               mon_group;
+       char            comma;
        char       *csymbol,
                                dsymbol,
                           *nsymbol;
@@ -237,32 +247,36 @@ cash_out(PG_FUNCTION_ARGS)
        if (lconvert == NULL)
                lconvert = localeconv();
 
+       /* see comments about frac_digits in cash_in() */
+       points = lconvert->frac_digits;
+       if (points < 0 || points > 10)
+               points = 2;                             /* best guess in this case, I think */
+
+       /*
+        * As with frac_digits, must apply a range check to mon_grouping
+        * to avoid being fooled by variant CHAR_MAX values.
+        */
        mon_group = *lconvert->mon_grouping;
+       if (mon_group <= 0 || mon_group > 6)
+               mon_group = 3;
+
        comma = ((*lconvert->mon_thousands_sep != '\0') ? *lconvert->mon_thousands_sep : ',');
-       /* frac_digits in the C locale seems to return CHAR_MAX */
-       /* best guess is 2 in this case I think */
-       points = ((lconvert->frac_digits != (char)CHAR_MAX) ? lconvert->frac_digits : 2); /* int_frac_digits? */
        convention = lconvert->n_sign_posn;
        dsymbol = ((*lconvert->mon_decimal_point != '\0') ? *lconvert->mon_decimal_point : '.');
        csymbol = ((*lconvert->currency_symbol != '\0') ? lconvert->currency_symbol : "$");
        nsymbol = ((*lconvert->negative_sign != '\0') ? lconvert->negative_sign : "-");
 #else
+       points = 2;
        mon_group = 3;
        comma = ',';
-       csymbol = "$";
+       convention = 0;
        dsymbol = '.';
+       csymbol = "$";
        nsymbol = "-";
-       points = 2;
-       convention = 0;
 #endif
 
        point_pos = LAST_DIGIT - points;
 
-       /* We're playing a little fast and loose with this.  Shoot me. */
-       /* Not me, that was the other guy. Haven't fixed it yet - thomas */
-       if (!mon_group || mon_group == (char)CHAR_MAX)
-               mon_group = 3;
-
        /* allow more than three decimal points and separate them */
        if (comma)
        {