psql replaces tabelator by spaces when table is printed. So data in tabular

format should not to contains tabulators. But some other data (like function
or procedures source code) should not be displayed in tabular format, and then
tabelators can be printed. The tabs breaks horizontal movement, so pspg does
described replacement too - similary like psql.

Author: okbob

src/table.c

@@ -678,6 +678,7 @@ readfile(Options *opts, DataDesc *desc, StateData *state)
 	bool		progressive_load_mode;
 	LineBuffer *rows;
 	int		clen = -1;
+	void	   *tabptr;
 
 #ifdef DEBUG_PIPE
 
@@ -831,6 +832,54 @@ readfile(Options *opts, DataDesc *desc, StateData *state)
 		}
 
 		read = remove_ansi_escape_seq(line, read);
+		if ((tabptr = memchr(line, '\t', read)))
+		{
+			int		tabcount = 1;
+			void   *endptr = line + read - 1;
+			char   *newline, *writeptr, *readptr;
+			int		total_dl = 0;
+
+			while ((tabptr = memchr(tabptr + 1, '\t', endptr - tabptr)))
+			{
+				tabcount += 1;
+			}
+
+			/* allocate enough memory for new line */
+			writeptr = newline = smalloc(read + tabcount * 8 + 1);
+			readptr = line;
+
+			while (read > 0)
+			{
+				if (*readptr == '\t')
+				{
+					do
+					{
+						*writeptr++ = ' ';
+						total_dl += 1;
+					} while (total_dl % 8 != 0);
+
+					read -= 1;
+					readptr += 1;
+				}
+				else
+				{
+					int		cl = charlen(readptr);
+					int		dl = dsplen(readptr);
+
+					total_dl += dl;
+					memcpy(writeptr, readptr, cl);
+					writeptr += cl;
+					readptr += cl;
+					read -= cl;
+				}
+			}
+
+			*writeptr = '\0';
+
+			free(line);
+			line = newline;
+			read = writeptr - newline;
+		}
 
 		/* In query stream node exit when you find row with only GS - Group Separator */
 		if (opts->querystream && read == 1)