Improve contrib/cube's handling of zero-D cubes, infinities, and NaNs.

It's always been possible to create a zero-dimensional cube by converting
from a zero-length float8 array, but cube_in failed to accept the '()'
representation that cube_out produced for that case, resulting in a
dump/reload hazard.  Make it accept the case.  Also fix a couple of
other places that didn't behave sanely for zero-dimensional cubes:
cube_size would produce 1.0 when surely the answer should be 0.0,
and g_cube_distance risked a divide-by-zero failure.

Likewise, it's always been possible to create cubes containing float8
infinity or NaN coordinate values, but cube_in couldn't parse such input,
and cube_out produced platform-dependent spellings of the values.  Convert
them to use float8in_internal and float8out_internal so that the behavior
will be the same as for float8, as we recently did for the core geometric
types (cf commit 50861cd68).  As in that commit, I don't pretend that this
patch fixes all insane corner-case behaviors that may exist for NaNs, but
it's a step forward.

(This change allows removal of the separate cube_1.out and cube_3.out
expected-files, as the platform dependency that previously required them
is now gone: an underflowing coordinate value will now produce an error
not plus or minus zero.)

Make errors from cube_in follow project conventions as to spelling
("invalid input syntax for cube" not "bad cube representation")
and errcode (INVALID_TEXT_REPRESENTATION not SYNTAX_ERROR).

Also a few marginal code cleanups and comment improvements.

Tom Lane, reviewed by Amul Sul

Discussion: <15085.1472494782@sss.pgh.pa.us>

1 files changed, 86 insertions, 62 deletions

diff --git a/contrib/cube/cubeparse.y b/contrib/cube/cubeparse.y
index 33606c741c..1b65fa967c 100644
--- a/contrib/cube/cubeparse.y
+++ b/contrib/cube/cubeparse.y
@@ -4,12 +4,13 @@
 /* NdBox = [(lowerleft),(upperright)] */
 /* [(xLL(1)...xLL(N)),(xUR(1)...xUR(n))] */
 
-#define YYSTYPE char *
-#define YYDEBUG 1
-
 #include "postgres.h"
 
 #include "cubedata.h"
+#include "utils/builtins.h"
+
+/* All grammar constructs return strings */
+#define YYSTYPE char *
 
 /*
  * Bison doesn't allocate anything that needs to live across parser calls,
@@ -25,9 +26,9 @@
 static char *scanbuf;
 static int	scanbuflen;
 
-static int delim_count(char *s, char delim);
-static NDBOX * write_box(unsigned int dim, char *str1, char *str2);
-static NDBOX * write_point_as_box(char *s, int dim);
+static int item_count(const char *s, char delim);
+static NDBOX *write_box(int dim, char *str1, char *str2);
+static NDBOX *write_point_as_box(int dim, char *str);
 
 %}
 
@@ -46,47 +47,48 @@ box: O_BRACKET paren_list COMMA paren_list C_BRACKET
 	{
 		int dim;
 
-		dim = delim_count($2, ',') + 1;
-		if ((delim_count($4, ',') + 1) != dim)
+		dim = item_count($2, ',');
+		if (item_count($4, ',') != dim)
 		{
 			ereport(ERROR,
-					(errcode(ERRCODE_SYNTAX_ERROR),
-					 errmsg("bad cube representation"),
+					(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+					 errmsg("invalid input syntax for cube"),
 					 errdetail("Different point dimensions in (%s) and (%s).",
 							   $2, $4)));
 			YYABORT;
 		}
-		if (dim > CUBE_MAX_DIM) {
+		if (dim > CUBE_MAX_DIM)
+		{
 			ereport(ERROR,
-					(errcode(ERRCODE_SYNTAX_ERROR),
-					 errmsg("bad cube representation"),
+					(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+					 errmsg("invalid input syntax for cube"),
 					 errdetail("A cube cannot have more than %d dimensions.",
 							   CUBE_MAX_DIM)));
 			YYABORT;
 		}
 
 		*result = write_box( dim, $2, $4 );
-
 	}
 
 	| paren_list COMMA paren_list
 	{
 		int dim;
 
-		dim = delim_count($1, ',') + 1;
-
-		if ( (delim_count($3, ',') + 1) != dim ) {
+		dim = item_count($1, ',');
+		if (item_count($3, ',') != dim)
+		{
 			ereport(ERROR,
-					(errcode(ERRCODE_SYNTAX_ERROR),
-					 errmsg("bad cube representation"),
+					(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+					 errmsg("invalid input syntax for cube"),
 					 errdetail("Different point dimensions in (%s) and (%s).",
 							   $1, $3)));
 			YYABORT;
 		}
-		if (dim > CUBE_MAX_DIM) {
+		if (dim > CUBE_MAX_DIM)
+		{
 			ereport(ERROR,
-					(errcode(ERRCODE_SYNTAX_ERROR),
-					 errmsg("bad cube representation"),
+					(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+					 errmsg("invalid input syntax for cube"),
 					 errdetail("A cube cannot have more than %d dimensions.",
 							   CUBE_MAX_DIM)));
 			YYABORT;
@@ -99,33 +101,36 @@ box: O_BRACKET paren_list COMMA paren_list C_BRACKET
 	{
 		int dim;
 
-		dim = delim_count($1, ',') + 1;
-		if (dim > CUBE_MAX_DIM) {
+		dim = item_count($1, ',');
+		if (dim > CUBE_MAX_DIM)
+		{
 			ereport(ERROR,
-					(errcode(ERRCODE_SYNTAX_ERROR),
-					 errmsg("bad cube representation"),
+					(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+					 errmsg("invalid input syntax for cube"),
 					 errdetail("A cube cannot have more than %d dimensions.",
 							   CUBE_MAX_DIM)));
 			YYABORT;
 		}
 
-		*result = write_point_as_box($1, dim);
+		*result = write_point_as_box(dim, $1);
 	}
 
 	| list
 	{
 		int dim;
 
-		dim = delim_count($1, ',') + 1;
-		if (dim > CUBE_MAX_DIM) {
+		dim = item_count($1, ',');
+		if (dim > CUBE_MAX_DIM)
+		{
 			ereport(ERROR,
-					(errcode(ERRCODE_SYNTAX_ERROR),
-					 errmsg("bad cube representation"),
+					(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+					 errmsg("invalid input syntax for cube"),
 					 errdetail("A cube cannot have more than %d dimensions.",
 							   CUBE_MAX_DIM)));
 			YYABORT;
 		}
-		*result = write_point_as_box($1, dim);
+
+		*result = write_point_as_box(dim, $1);
 	}
 	;
 
@@ -133,6 +138,10 @@ paren_list: O_PAREN list C_PAREN
 	{
 		$$ = $2;
 	}
+	| O_PAREN C_PAREN
+	{
+		$$ = pstrdup("");
+	}
 	;
 
 list: CUBEFLOAT
@@ -151,24 +160,30 @@ list: CUBEFLOAT
 
 %%
 
+/* This assumes the string has been normalized by productions above */
 static int
-delim_count(char *s, char delim)
+item_count(const char *s, char delim)
 {
-	int			ndelim = 0;
+	int			nitems = 0;
 
-	while ((s = strchr(s, delim)) != NULL)
+	if (s[0] != '\0')
 	{
-		ndelim++;
-		s++;
+		nitems++;
+		while ((s = strchr(s, delim)) != NULL)
+		{
+			nitems++;
+			s++;
+		}
 	}
-	return (ndelim);
+	return nitems;
 }
 
 static NDBOX *
-write_box(unsigned int dim, char *str1, char *str2)
+write_box(int dim, char *str1, char *str2)
 {
 	NDBOX	   *bp;
 	char	   *s;
+	char	   *endptr;
 	int			i;
 	int			size = CUBE_SIZE(dim);
 	bool		point = true;
@@ -178,50 +193,58 @@ write_box(unsigned int dim, char *str1, char *str2)
 	SET_DIM(bp, dim);
 
 	s = str1;
-	bp->x[i=0] = strtod(s, NULL);
+	i = 0;
+	if (dim > 0)
+		bp->x[i++] = float8in_internal(s, &endptr, "cube", str1);
 	while ((s = strchr(s, ',')) != NULL)
 	{
-		s++; i++;
-		bp->x[i] = strtod(s, NULL);
+		s++;
+		bp->x[i++] = float8in_internal(s, &endptr, "cube", str1);
 	}
+	Assert(i == dim);
 
 	s = str2;
-	bp->x[i=dim] = strtod(s, NULL);
-	if (bp->x[dim] != bp->x[0])
-		point = false;
+	if (dim > 0)
+	{
+		bp->x[i] = float8in_internal(s, &endptr, "cube", str2);
+		/* code this way to do right thing with NaN */
+		point &= (bp->x[i] == bp->x[0]);
+		i++;
+	}
 	while ((s = strchr(s, ',')) != NULL)
 	{
-		s++; i++;
-		bp->x[i] = strtod(s, NULL);
-		if (bp->x[i] != bp->x[i-dim])
-			point = false;
+		s++;
+		bp->x[i] = float8in_internal(s, &endptr, "cube", str2);
+		point &= (bp->x[i] == bp->x[i - dim]);
+		i++;
 	}
+	Assert(i == dim * 2);
 
 	if (point)
 	{
 		/*
 		 * The value turned out to be a point, ie. all the upper-right
 		 * coordinates were equal to the lower-left coordinates. Resize the
-		 * the cube we constructed. Note: we don't bother to repalloc() it
-		 * smaller, it's unlikely that the tiny amount of memory free'd that
-		 * way would be useful.
+		 * cube we constructed.  Note: we don't bother to repalloc() it
+		 * smaller, as it's unlikely that the tiny amount of memory freed
+		 * that way would be useful, and the output is always short-lived.
 		 */
 		size = POINT_SIZE(dim);
 		SET_VARSIZE(bp, size);
 		SET_POINT_BIT(bp);
 	}
 
-	return(bp);
+	return bp;
 }
 
 static NDBOX *
-write_point_as_box(char *str, int dim)
+write_point_as_box(int dim, char *str)
 {
 	NDBOX		*bp;
 	int			i,
 				size;
-	double		x;
-	char		*s = str;
+	char	   *s;
+	char	   *endptr;
 
 	size = POINT_SIZE(dim);
 	bp = palloc0(size);
@@ -229,17 +252,18 @@ write_point_as_box(char *str, int dim)
 	SET_DIM(bp, dim);
 	SET_POINT_BIT(bp);
 
+	s = str;
 	i = 0;
-	x = strtod(s, NULL);
-	bp->x[0] = x;
+	if (dim > 0)
+		bp->x[i++] = float8in_internal(s, &endptr, "cube", str);
 	while ((s = strchr(s, ',')) != NULL)
 	{
-		s++; i++;
-		x = strtod(s, NULL);
-		bp->x[i] = x;
+		s++;
+		bp->x[i++] = float8in_internal(s, &endptr, "cube", str);
 	}
+	Assert(i == dim);
 
-	return(bp);
+	return bp;
 }
 
 #include "cubescan.c"