Make sure float4in/float8in accept all standard spellings of "infinity".

The C99 and POSIX standards require strtod() to accept all these spellings
(case-insensitively): "inf", "+inf", "-inf", "infinity", "+infinity",
"-infinity".  However, pre-C99 systems might accept only some or none of
these, and apparently Windows still doesn't accept "inf".  To avoid
surprising cross-platform behavioral differences, manually check for each
of these spellings if strtod() fails.  We were previously handling just
"infinity" and "-infinity" that way, but since C99 is most of the world
now, it seems likely that applications are expecting all these spellings
to work.

Per bug #8355 from Basil Peace.  It turns out this fix won't actually
resolve his problem, because Python isn't being this careful; but that
doesn't mean we shouldn't be.

diff --git a/src/backend/utils/adt/float.c b/src/backend/utils/adt/float.c
index 4547240be1f74f86292492c547e6a0598c0e373e..41e4236c1eea01e474a810a2078ac4e2eceb2994 100644 (file)
--- a/src/backend/utils/adt/float.c
+++ b/src/backend/utils/adt/float.c
@@ -174,11 +174,7 @@ is_infinite(double val)
 
 
 /*
- *             float4in                - converts "num" to float
- *                                               restricted syntax:
- *                                               {<sp>} [+|-] {digit} [.{digit}] [<exp>]
- *                                               where <sp> is a space, digit is 0-9,
- *                                               <exp> is "e" or "E" followed by an integer.
+ *             float4in                - converts "num" to float4
  */
 Datum
 float4in(PG_FUNCTION_ARGS)
@@ -195,6 +191,10 @@ float4in(PG_FUNCTION_ARGS)
         */
        orig_num = num;
 
+       /* skip leading whitespace */
+       while (*num != '\0' && isspace((unsigned char) *num))
+               num++;
+
        /*
         * Check for an empty-string input to begin with, to avoid the vagaries of
         * strtod() on different platforms.
@@ -205,20 +205,23 @@ float4in(PG_FUNCTION_ARGS)
                                 errmsg("invalid input syntax for type real: \"%s\"",
                                                orig_num)));
 
-       /* skip leading whitespace */
-       while (*num != '\0' && isspace((unsigned char) *num))
-               num++;
-
        errno = 0;
        val = strtod(num, &endptr);
 
        /* did we not see anything that looks like a double? */
        if (endptr == num || errno != 0)
        {
+               int                     save_errno = errno;
+
                /*
-                * C99 requires that strtod() accept NaN and [-]Infinity, but not all
-                * platforms support that yet (and some accept them but set ERANGE
-                * anyway...)  Therefore, we check for these inputs ourselves.
+                * C99 requires that strtod() accept NaN, [+-]Infinity, and [+-]Inf,
+                * but not all platforms support all of these (and some accept them
+                * but set ERANGE anyway...)  Therefore, we check for these inputs
+                * ourselves if strtod() fails.
+                *
+                * Note: C99 also requires hexadecimal input as well as some extended
+                * forms of NaN, but we consider these forms unportable and don't try
+                * to support them.  You can use 'em if your strtod() takes 'em.
                 */
                if (pg_strncasecmp(num, "NaN", 3) == 0)
                {
@@ -230,12 +233,32 @@ float4in(PG_FUNCTION_ARGS)
                        val = get_float4_infinity();
                        endptr = num + 8;
                }
+               else if (pg_strncasecmp(num, "+Infinity", 9) == 0)
+               {
+                       val = get_float4_infinity();
+                       endptr = num + 9;
+               }
                else if (pg_strncasecmp(num, "-Infinity", 9) == 0)
                {
                        val = -get_float4_infinity();
                        endptr = num + 9;
                }
-               else if (errno == ERANGE)
+               else if (pg_strncasecmp(num, "inf", 3) == 0)
+               {
+                       val = get_float4_infinity();
+                       endptr = num + 3;
+               }
+               else if (pg_strncasecmp(num, "+inf", 4) == 0)
+               {
+                       val = get_float4_infinity();
+                       endptr = num + 4;
+               }
+               else if (pg_strncasecmp(num, "-inf", 4) == 0)
+               {
+                       val = -get_float4_infinity();
+                       endptr = num + 4;
+               }
+               else if (save_errno == ERANGE)
                        ereport(ERROR,
                                        (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
                                         errmsg("\"%s\" is out of range for type real",
@@ -273,6 +296,11 @@ float4in(PG_FUNCTION_ARGS)
                        val = get_float4_infinity();
                        endptr = num + 8;
                }
+               else if (pg_strncasecmp(num, "+Infinity", 9) == 0)
+               {
+                       val = get_float4_infinity();
+                       endptr = num + 9;
+               }
                else if (pg_strncasecmp(num, "-Infinity", 9) == 0)
                {
                        val = -get_float4_infinity();
@@ -368,10 +396,6 @@ float4send(PG_FUNCTION_ARGS)
 
 /*
  *             float8in                - converts "num" to float8
- *                                               restricted syntax:
- *                                               {<sp>} [+|-] {digit} [.{digit}] [<exp>]
- *                                               where <sp> is a space, digit is 0-9,
- *                                               <exp> is "e" or "E" followed by an integer.
  */
 Datum
 float8in(PG_FUNCTION_ARGS)
@@ -388,6 +412,10 @@ float8in(PG_FUNCTION_ARGS)
         */
        orig_num = num;
 
+       /* skip leading whitespace */
+       while (*num != '\0' && isspace((unsigned char) *num))
+               num++;
+
        /*
         * Check for an empty-string input to begin with, to avoid the vagaries of
         * strtod() on different platforms.
@@ -398,20 +426,23 @@ float8in(PG_FUNCTION_ARGS)
                         errmsg("invalid input syntax for type double precision: \"%s\"",
                                        orig_num)));
 
-       /* skip leading whitespace */
-       while (*num != '\0' && isspace((unsigned char) *num))
-               num++;
-
        errno = 0;
        val = strtod(num, &endptr);
 
        /* did we not see anything that looks like a double? */
        if (endptr == num || errno != 0)
        {
+               int                     save_errno = errno;
+
                /*
-                * C99 requires that strtod() accept NaN and [-]Infinity, but not all
-                * platforms support that yet (and some accept them but set ERANGE
-                * anyway...)  Therefore, we check for these inputs ourselves.
+                * C99 requires that strtod() accept NaN, [+-]Infinity, and [+-]Inf,
+                * but not all platforms support all of these (and some accept them
+                * but set ERANGE anyway...)  Therefore, we check for these inputs
+                * ourselves if strtod() fails.
+                *
+                * Note: C99 also requires hexadecimal input as well as some extended
+                * forms of NaN, but we consider these forms unportable and don't try
+                * to support them.  You can use 'em if your strtod() takes 'em.
                 */
                if (pg_strncasecmp(num, "NaN", 3) == 0)
                {
@@ -423,12 +454,32 @@ float8in(PG_FUNCTION_ARGS)
                        val = get_float8_infinity();
                        endptr = num + 8;
                }
+               else if (pg_strncasecmp(num, "+Infinity", 9) == 0)
+               {
+                       val = get_float8_infinity();
+                       endptr = num + 9;
+               }
                else if (pg_strncasecmp(num, "-Infinity", 9) == 0)
                {
                        val = -get_float8_infinity();
                        endptr = num + 9;
                }
-               else if (errno == ERANGE)
+               else if (pg_strncasecmp(num, "inf", 3) == 0)
+               {
+                       val = get_float8_infinity();
+                       endptr = num + 3;
+               }
+               else if (pg_strncasecmp(num, "+inf", 4) == 0)
+               {
+                       val = get_float8_infinity();
+                       endptr = num + 4;
+               }
+               else if (pg_strncasecmp(num, "-inf", 4) == 0)
+               {
+                       val = -get_float8_infinity();
+                       endptr = num + 4;
+               }
+               else if (save_errno == ERANGE)
                        ereport(ERROR,
                                        (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
                                   errmsg("\"%s\" is out of range for type double precision",
@@ -466,6 +517,11 @@ float8in(PG_FUNCTION_ARGS)
                        val = get_float8_infinity();
                        endptr = num + 8;
                }
+               else if (pg_strncasecmp(num, "+Infinity", 9) == 0)
+               {
+                       val = get_float8_infinity();
+                       endptr = num + 9;
+               }
                else if (pg_strncasecmp(num, "-Infinity", 9) == 0)
                {
                        val = -get_float8_infinity();