Tighened up syntax checking of array input processing considerably. Junk that

was previously allowed in odd places with odd results now causes an ERROR.
Also changed behavior with respect to whitespace -- trailing whitespace is
now ignored as well as leading whitespace (which has always been ignored).

Documentation updated to reflect change in whitespace handling. Also some
refactoring to what I believe is a more sensible order of several paragraphs.

doc/src/sgml/array.sgml

-<!-- $PostgreSQL: pgsql/doc/src/sgml/array.sgml,v 1.36 2004/08/05 03:29:11 joe Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/array.sgml,v 1.37 2004/08/08 05:01:51 joe Exp $ -->
 
 <sect1 id="arrays">
  <title>Arrays</title>
@@ -95,10 +95,12 @@ CREATE TABLE tictactoe (
 </synopsis>
    where <replaceable>delim</replaceable> is the delimiter character
    for the type, as recorded in its <literal>pg_type</literal> entry.
-   (For all built-in types, this is the comma character
-   <quote><literal>,</literal></>.)  Each
-   <replaceable>val</replaceable> is either a constant of the array
-   element type, or a subarray.  An example of an array constant is
+   Among the standard data types provided in the
+   <productname>PostgreSQL</productname> distribution, type
+   <literal>box</> uses a semicolon (<literal>;</>) but all the others
+   use comma (<literal>,</>). Each <replaceable>val</replaceable> is
+   either a constant of the array element type, or a subarray. An example
+   of an array constant is
 <programlisting>
 '{{1,2,3},{4,5,6},{7,8,9}}'
 </programlisting>
@@ -161,7 +163,7 @@ SELECT * FROM sal_emp;
  </para>
 
  <para>
-  The <literal>ARRAY</literal> expression syntax may also be used:
+  The <literal>ARRAY</> constructor syntax may also be used:
 <programlisting>
 INSERT INTO sal_emp
     VALUES ('Bill',
@@ -176,8 +178,8 @@ INSERT INTO sal_emp
   Notice that the array elements are ordinary SQL constants or
   expressions; for instance, string literals are single quoted, instead of
   double quoted as they would be in an array literal.  The <literal>ARRAY</>
-  expression syntax is discussed in more detail in <xref
-  linkend="sql-syntax-array-constructors">.
+  constructor syntax is discussed in more detail in
+  <xref linkend="sql-syntax-array-constructors">.
  </para>
  </sect2>
 
@@ -524,10 +526,17 @@ SELECT * FROM sal_emp WHERE 10000 = ALL (pay_by_quarter);
    use comma.)  In a multidimensional array, each dimension (row, plane,
    cube, etc.) gets its own level of curly braces, and delimiters
    must be written between adjacent curly-braced entities of the same level.
-   You may write whitespace before a left brace, after a right
-   brace, or before any individual item string.  Whitespace after an item
-   is not ignored, however: after skipping leading whitespace, everything
-   up to the next right brace or delimiter is taken as the item value.
+  </para>
+
+  <para>
+   The array output routine will put double quotes around element values
+   if they are empty strings or contain curly braces, delimiter characters,
+   double quotes, backslashes, or white space.  Double quotes and backslashes
+   embedded in element values will be backslash-escaped.  For numeric
+   data types it is safe to assume that double quotes will never appear, but
+   for textual data types one should be prepared to cope with either presence
+   or absence of quotes.  (This is a change in behavior from pre-7.2
+   <productname>PostgreSQL</productname> releases.)
   </para>
 
   <para>
@@ -573,26 +582,22 @@ SELECT f1[1][-2][3] AS e1, f1[1][-1][5] AS e2
 
   <para>
    As shown previously, when writing an array value you may write double
-   quotes around any individual array
-   element.  You <emphasis>must</> do so if the element value would otherwise
-   confuse the array-value parser.  For example, elements containing curly
-   braces, commas (or whatever the delimiter character is), double quotes,
-   backslashes, or leading white space must be double-quoted.  To put a double
-   quote or backslash in a quoted array element value, precede it with a
-   backslash.
-   Alternatively, you can use backslash-escaping to protect all data characters
-   that would otherwise be taken as array syntax or ignorable white space.
+   quotes around any individual array element. You <emphasis>must</> do so
+   if the element value would otherwise confuse the array-value parser.
+   For example, elements containing curly braces, commas (or whatever the
+   delimiter character is), double quotes, backslashes, or leading white
+   space must be double-quoted.  To put a double quote or backslash in a
+   quoted array element value, precede it with a backslash. Alternatively,
+   you can use backslash-escaping to protect all data characters that would
+   otherwise be taken as array syntax.
   </para>
 
   <para>
-   The array output routine will put double quotes around element values
-   if they are empty strings or contain curly braces, delimiter characters,
-   double quotes, backslashes, or white space.  Double quotes and backslashes
-   embedded in element values will be backslash-escaped.  For numeric
-   data types it is safe to assume that double quotes will never appear, but
-   for textual data types one should be prepared to cope with either presence
-   or absence of quotes.  (This is a change in behavior from pre-7.2
-   <productname>PostgreSQL</productname> releases.)
+   You may write whitespace before a left brace or after a right
+   brace. You may also write whitespace before or after any individual item
+   string. In all of these cases the whitespace will be ignored. However,
+   whitespace within double quoted elements, or surrounded on both sides by
+   non-whitespace characters of an element, are not ignored.
   </para>
 
  <note>
@@ -616,10 +621,11 @@ INSERT ... VALUES ('{"\\\\","\\""}');
 
  <tip>
   <para>
-   The <literal>ARRAY</> constructor syntax is often easier to work with
-   than the array-literal syntax when writing array values in SQL commands.
-   In <literal>ARRAY</>, individual element values are written the same way
-   they would be written when not members of an array.
+   The <literal>ARRAY</> constructor syntax (see
+   <xref linkend="sql-syntax-array-constructors">) is often easier to work
+   with than the array-literal syntax when writing array values in SQL
+   commands. In <literal>ARRAY</>, individual element values are written the
+   same way they would be written when not members of an array.
   </para>
  </tip>
  </sect2>

src/backend/utils/adt/arrayfuncs.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/arrayfuncs.c,v 1.106 2004/08/05 03:29:37 joe Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/arrayfuncs.c,v 1.107 2004/08/08 05:01:55 joe Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -351,18 +351,32 @@ array_in(PG_FUNCTION_ARGS)
  *		 The syntax for array input is C-like nested curly braces
  *-----------------------------------------------------------------------------
  */
+typedef enum
+{
+	ARRAY_NO_LEVEL,
+	ARRAY_LEVEL_STARTED,
+	ARRAY_ELEM_STARTED,
+	ARRAY_ELEM_COMPLETED,
+	ARRAY_QUOTED_ELEM_STARTED,
+	ARRAY_QUOTED_ELEM_COMPLETED,
+	ARRAY_ELEM_DELIMITED,
+	ARRAY_LEVEL_COMPLETED,
+	ARRAY_LEVEL_DELIMITED
+} ArrayParseState;
+
 static int
 ArrayCount(char *str, int *dim, char typdelim)
 {
-	int			nest_level = 0,
-				i;
-	int			ndim = 1,
-				temp[MAXDIM],
-				nelems[MAXDIM],
-				nelems_last[MAXDIM];
-	bool		scanning_string = false;
-	bool		eoArray = false;
-	char	   *ptr;
+	int				nest_level = 0,
+					i;
+	int				ndim = 1,
+					temp[MAXDIM],
+					nelems[MAXDIM],
+					nelems_last[MAXDIM];
+	bool			scanning_string = false;
+	bool			eoArray = false;
+	char		   *ptr;
+	ArrayParseState	parse_state = ARRAY_NO_LEVEL;
 
 	for (i = 0; i < MAXDIM; ++i)
 	{
@@ -370,6 +384,7 @@ ArrayCount(char *str, int *dim, char typdelim)
 		nelems_last[i] = nelems[i] = 1;
 	}
 
+	/* special case for an empty array */
 	if (strncmp(str, "{}", 2) == 0)
 		return 0;
 
@@ -389,6 +404,20 @@ ArrayCount(char *str, int *dim, char typdelim)
 						errmsg("malformed array literal: \"%s\"", str)));
 					break;
 				case '\\':
+					/*
+					 * An escape must be after a level start, after an
+					 * element start, or after an element delimiter. In any
+					 * case we now must be past an element start.
+					 */
+					if (parse_state != ARRAY_LEVEL_STARTED &&
+						parse_state != ARRAY_ELEM_STARTED &&
+						parse_state != ARRAY_QUOTED_ELEM_STARTED &&
+						parse_state != ARRAY_ELEM_DELIMITED)
+						ereport(ERROR,
+							(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+							errmsg("malformed array literal: \"%s\"", str)));
+					if (parse_state != ARRAY_QUOTED_ELEM_STARTED)
+						parse_state = ARRAY_ELEM_STARTED;
 					/* skip the escaped character */
 					if (*(ptr + 1))
 						ptr++;
@@ -398,11 +427,38 @@ ArrayCount(char *str, int *dim, char typdelim)
 						errmsg("malformed array literal: \"%s\"", str)));
 					break;
 				case '\"':
+					/*
+					 * A quote must be after a level start, after a quoted
+					 * element start, or after an element delimiter. In any
+					 * case we now must be past an element start.
+					 */
+					if (parse_state != ARRAY_LEVEL_STARTED &&
+						parse_state != ARRAY_QUOTED_ELEM_STARTED &&
+						parse_state != ARRAY_ELEM_DELIMITED)
+						ereport(ERROR,
+							(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+							errmsg("malformed array literal: \"%s\"", str)));
 					scanning_string = !scanning_string;
+					if (scanning_string)
+						parse_state = ARRAY_QUOTED_ELEM_STARTED;
+					else
+						parse_state = ARRAY_QUOTED_ELEM_COMPLETED;
 					break;
 				case '{':
 					if (!scanning_string)
 					{
+						/*
+						 * A left brace can occur if no nesting has
+						 * occurred yet, after a level start, or
+						 * after a level delimiter.
+						 */
+						if (parse_state != ARRAY_NO_LEVEL &&
+							parse_state != ARRAY_LEVEL_STARTED &&
+							parse_state != ARRAY_LEVEL_DELIMITED)
+							ereport(ERROR,
+								(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+								errmsg("malformed array literal: \"%s\"", str)));
+						parse_state = ARRAY_LEVEL_STARTED;
 						if (nest_level >= MAXDIM)
 							ereport(ERROR,
 								(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
@@ -417,6 +473,19 @@ ArrayCount(char *str, int *dim, char typdelim)
 				case '}':
 					if (!scanning_string)
 					{
+						/*
+						 * A right brace can occur after an element start,
+						 * an element completion, a quoted element completion,
+						 * or a level completion.
+						 */
+						if (parse_state != ARRAY_ELEM_STARTED &&
+							parse_state != ARRAY_ELEM_COMPLETED &&
+							parse_state != ARRAY_QUOTED_ELEM_COMPLETED &&
+							parse_state != ARRAY_LEVEL_COMPLETED)
+							ereport(ERROR,
+								(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+								errmsg("malformed array literal: \"%s\"", str)));
+						parse_state = ARRAY_LEVEL_COMPLETED;
 						if (nest_level == 0)
 							ereport(ERROR,
 							(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
@@ -445,10 +514,45 @@ ArrayCount(char *str, int *dim, char typdelim)
 					}
 					break;
 				default:
-					if (*ptr == typdelim && !scanning_string)
+					if (!scanning_string)
 					{
-						itemdone = true;
-						nelems[nest_level - 1]++;
+						if (*ptr == typdelim)
+						{
+							/*
+							* Delimiters can occur after an element start,
+							* an element completion, a quoted element
+							* completion, or a level completion.
+							*/
+							if (parse_state != ARRAY_ELEM_STARTED &&
+								parse_state != ARRAY_ELEM_COMPLETED &&
+								parse_state != ARRAY_QUOTED_ELEM_COMPLETED &&
+								parse_state != ARRAY_LEVEL_COMPLETED)
+								ereport(ERROR,
+									(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+									errmsg("malformed array literal: \"%s\"", str)));
+							if (parse_state == ARRAY_LEVEL_COMPLETED)
+								parse_state = ARRAY_LEVEL_DELIMITED;
+							else
+								parse_state = ARRAY_ELEM_DELIMITED;
+							itemdone = true;
+							nelems[nest_level - 1]++;
+						}
+						else if (!isspace(*ptr))
+						{
+							/*
+							* Other non-space characters must be after a level
+							* start, after an element start, or after an element
+							* delimiter. In any case we now must be past an
+							* element start.
+							*/
+							if (parse_state != ARRAY_LEVEL_STARTED &&
+								parse_state != ARRAY_ELEM_STARTED &&
+								parse_state != ARRAY_ELEM_DELIMITED)
+								ereport(ERROR,
+									(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+									errmsg("malformed array literal: \"%s\"", str)));
+							parse_state = ARRAY_ELEM_STARTED;
+						}
 					}
 					break;
 			}
@@ -511,12 +615,15 @@ ReadArrayStr(char *arrayStr,
 	while (!eoArray)
 	{
 		bool		itemdone = false;
+		bool		itemquoted = false;
 		int			i = -1;
 		char	   *itemstart;
+		char	   *eptr;
 
 		/* skip leading whitespace */
 		while (isspace((unsigned char) *ptr))
 			ptr++;
+
 		itemstart = ptr;
 
 		while (!itemdone)
@@ -547,11 +654,15 @@ ReadArrayStr(char *arrayStr,
 						char	   *cptr;
 
 						scanning_string = !scanning_string;
-						/* Crunch the string on top of the quote. */
-						for (cptr = ptr; *cptr != '\0'; cptr++)
-							*cptr = *(cptr + 1);
-						/* Back up to not miss following character. */
-						ptr--;
+						if (scanning_string)
+						{
+							itemquoted = true;
+							/* Crunch the string on top of the first quote. */
+							for (cptr = ptr; *cptr != '\0'; cptr++)
+								*cptr = *(cptr + 1);
+							/* Back up to not miss following character. */
+							ptr--;
+						}
 						break;
 					}
 				case '{':
@@ -615,6 +726,25 @@ ReadArrayStr(char *arrayStr,
 					(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
 				   errmsg("malformed array literal: \"%s\"", arrayStr)));
 
+		/*
+		 * skip trailing whitespace
+		 */
+		eptr = ptr - 1;
+		if (!itemquoted)
+		{
+			/* skip to last non-NULL, non-space, character */
+			while ((*eptr == '\0') || (isspace((unsigned char) *eptr)))
+				eptr--;
+			*(++eptr) = '\0';
+		}
+		else
+		{
+			/* skip to last quote character */
+			while (*eptr != '"')
+				eptr--;
+			*eptr = '\0';
+		}
+
 		values[i] = FunctionCall3(inputproc,
 								  CStringGetDatum(itemstart),
 								  ObjectIdGetDatum(typioparam),