Add regression tests for CSV and \., and add automatic quoting of a

single column dump that has a \. value, so the load works properly.  I
also added documentation describing this issue.

doc/src/sgml/ref/copy.sgml

 <!--
-$PostgreSQL: pgsql/doc/src/sgml/ref/copy.sgml,v 1.70 2005/10/15 20:12:33 neilc Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/copy.sgml,v 1.71 2005/12/28 03:25:32 momjian Exp $
 PostgreSQL documentation
 -->
 
@@ -511,6 +511,17 @@ COPY <replaceable class="parameter">tablename</replaceable> [ ( <replaceable cla
     comparisons for specific columns.
    </para>
 
+   <para> 
+    Because backslash is not a special character in the <literal>CSV</>
+    format, <literal>\.</>, the end-of-data marker, could also appear
+    as a data value.  To avoid any misinterpretation, a <literal>\.</>
+    data value appearing as a lone entry on a line is automatically 
+    quoted on output, and on input, if quoted, is not interpreted as the 
+    end-of-data marker.  If you are loading a single-column table that
+    might have a column value of <literal>\.</>, you might need to quote
+    that value in the input file.
+   </para>
+
    <note>
     <para>
      In <literal>CSV</> mode, all characters are significant. A quoted value 

src/backend/commands/copy.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/copy.c,v 1.256 2005/12/27 18:10:48 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/copy.c,v 1.257 2005/12/28 03:25:32 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -244,7 +244,7 @@ static Datum CopyReadBinaryAttribute(CopyState cstate,
 						bool *isnull);
 static void CopyAttributeOutText(CopyState cstate, char *server_string);
 static void CopyAttributeOutCSV(CopyState cstate, char *server_string,
-					bool use_quote);
+					bool use_quote, bool single_attr);
 static List *CopyGetAttnums(Relation rel, List *attnamelist);
 static char *limit_printout_length(const char *str);
 
@@ -1284,7 +1284,8 @@ CopyTo(CopyState cstate)
 
 				colname = NameStr(attr[attnum - 1]->attname);
 
-				CopyAttributeOutCSV(cstate, colname, false);
+				CopyAttributeOutCSV(cstate, colname, false,
+									list_length(cstate->attnumlist) == 1);
 			}
 
 			CopySendEndOfRow(cstate);
@@ -1359,7 +1360,8 @@ CopyTo(CopyState cstate)
 														   value));
 					if (cstate->csv_mode)
 						CopyAttributeOutCSV(cstate, string,
-											force_quote[attnum - 1]);
+											force_quote[attnum - 1],
+											list_length(cstate->attnumlist) == 1);
 					else
 						CopyAttributeOutText(cstate, string);
 				}
@@ -2968,7 +2970,7 @@ CopyAttributeOutText(CopyState cstate, char *server_string)
  */
 static void
 CopyAttributeOutCSV(CopyState cstate, char *server_string,
-					bool use_quote)
+					bool use_quote, bool single_attr)
 {
 	char	   *string;
 	char		c;
@@ -2992,6 +2994,15 @@ CopyAttributeOutCSV(CopyState cstate, char *server_string,
 	 * quoting, second to actually send it
 	 */
 	if (!use_quote)
+	{
+		/*
+		 *	Because '\.' can be a data value, quote it if it appears
+		 *	alone on a line so it is not interpreted as the end-of-data
+		 *	marker.
+		 */
+		if (single_attr && strcmp(string, "\\.") == 0)
+ 			use_quote = true;
+ 		else
  		{
 			for (tstring = string; (c = *tstring) != '\0'; tstring += mblen)
 			{
@@ -3006,6 +3017,7 @@ CopyAttributeOutCSV(CopyState cstate, char *server_string,
 					mblen = 1;
 			}
 		}
+	}
 
 	if (use_quote)
 		CopySendChar(cstate, quotec);

src/test/regress/expected/copy2.out

@@ -194,6 +194,9 @@ COPY y TO stdout WITH CSV FORCE QUOTE col2 ESCAPE E'\\';
 --test that we read consecutive LFs properly
 CREATE TEMP TABLE testnl (a int, b text, c int);
 COPY testnl FROM stdin CSV;
+-- test end of copy marker
+CREATE TEMP TABLE testeoc (a text);
+COPY testeoc FROM stdin CSV;
 DROP TABLE x, y;
 DROP FUNCTION fn_x_before();
 DROP FUNCTION fn_x_after();

src/test/regress/sql/copy2.sql

@@ -139,6 +139,16 @@ COPY testnl FROM stdin CSV;
 inside",2
 \.
 
+-- test end of copy marker
+CREATE TEMP TABLE testeoc (a text);
+
+COPY testeoc FROM stdin CSV;
+a\.
+\.b
+c\.d
+"\."
+\.
+
 
 DROP TABLE x, y;
 DROP FUNCTION fn_x_before();