- Fix a regression bug on (XML) HTML tables.

modified:
  tabxml.cpp
added:
  xml_html.test
  xml_html.result
  beers.xml
  coffee.htm

- Fix MDEV-7935 by suppressing error resetting code in delete_or_rename_table.
  However, the issue is that this code was added because without it an assertion
  was raised in some cases. Unfortunately I can't remember what were these cases.
  Therefore fixing it in this case will perhaps make a new crash happening on another cases.
modified:
  ha_connect.cc

- Add the UDF Json_Array_Delete.
modified:
  jsonudf.cpp

7 files changed, 201 insertions, 18 deletions

diff --git a/storage/connect/ha_connect.cc b/storage/connect/ha_connect.cc
index 8b1ca3519ee..765c04bd2be 100644
--- a/storage/connect/ha_connect.cc
+++ b/storage/connect/ha_connect.cc
@@ -4632,8 +4632,13 @@ int ha_connect::delete_or_rename_table(const char *name, const char *to)
 
         } // endif pos
 
-    } else       // Avoid infamous DBUG_ASSERT
-      thd->get_stmt_da()->reset_diagnostics_area();
+      } // endif open_table_def
+
+//  This below was done to avoid DBUG_ASSERT in some case that
+//  we don't know anymore what they were. It was suppressed because
+//  it did cause assertion in other cases (see MDEV-7935)
+//  } else       // Avoid infamous DBUG_ASSERT
+//    thd->get_stmt_da()->reset_diagnostics_area();
 
     free_table_share(share);
   } else              // Temporary file
diff --git a/storage/connect/jsonudf.cpp b/storage/connect/jsonudf.cpp
index 194cb6defd6..1afd79bec05 100644
--- a/storage/connect/jsonudf.cpp
+++ b/storage/connect/jsonudf.cpp
@@ -17,40 +17,45 @@
 #include "json.h"
 
 #define MEMFIX  512
+#define UDF_EXEC_ARGS \
+  UDF_INIT*, UDF_ARGS*, char*, unsigned long*, char*, char* 
 
 uint GetJsonGrpSize(void);
 
 extern "C" {
 DllExport my_bool Json_Value_init(UDF_INIT*, UDF_ARGS*, char*);
-DllExport char *Json_Value(UDF_INIT*, UDF_ARGS*, char*,
-                         unsigned long*, char *, char *);
+DllExport char *Json_Value(UDF_EXEC_ARGS);
 DllExport void Json_Value_deinit(UDF_INIT*);
+
 DllExport my_bool Json_Array_init(UDF_INIT*, UDF_ARGS*, char*);
-DllExport char *Json_Array(UDF_INIT*, UDF_ARGS*, char*,
-                         unsigned long*, char *, char *);
+DllExport char *Json_Array(UDF_EXEC_ARGS);
 DllExport void Json_Array_deinit(UDF_INIT*);
+
 DllExport my_bool Json_Array_Add_init(UDF_INIT*, UDF_ARGS*, char*);
-DllExport char *Json_Array_Add(UDF_INIT*, UDF_ARGS*, char*,
-                         unsigned long*, char *, char *);
+DllExport char *Json_Array_Add(UDF_EXEC_ARGS);
 DllExport void Json_Array_Add_deinit(UDF_INIT*);
+
+DllExport my_bool Json_Array_Delete_init(UDF_INIT*, UDF_ARGS*, char*);
+DllExport char *Json_Array_Delete(UDF_EXEC_ARGS);
+DllExport void Json_Array_Delete_deinit(UDF_INIT*);
+
 DllExport my_bool Json_Object_init(UDF_INIT*, UDF_ARGS*, char*);
-DllExport char *Json_Object(UDF_INIT*, UDF_ARGS*, char*,
-                         unsigned long*, char *, char *);
+DllExport char *Json_Object(UDF_EXEC_ARGS);
 DllExport void Json_Object_deinit(UDF_INIT*);
+
 DllExport my_bool Json_Object_Nonull_init(UDF_INIT*, UDF_ARGS*, char*);
-DllExport char *Json_Object_Nonull(UDF_INIT*, UDF_ARGS*, char*,
-                         unsigned long*, char *, char *);
+DllExport char *Json_Object_Nonull(UDF_EXEC_ARGS);
 DllExport void Json_Object_Nonull_deinit(UDF_INIT*);
+
 DllExport my_bool Json_Array_Grp_init(UDF_INIT*, UDF_ARGS*, char*);
 DllExport void Json_Array_Grp_add(UDF_INIT *, UDF_ARGS *, char *, char *);
-DllExport char *Json_Array_Grp(UDF_INIT*, UDF_ARGS*, char*,
-                         unsigned long*, char *, char *);
+DllExport char *Json_Array_Grp(UDF_EXEC_ARGS);
 DllExport void Json_Array_Grp_clear(UDF_INIT *, char *, char *);
 DllExport void Json_Array_Grp_deinit(UDF_INIT*);
+
 DllExport my_bool Json_Object_Grp_init(UDF_INIT*, UDF_ARGS*, char*);
 DllExport void Json_Object_Grp_add(UDF_INIT *, UDF_ARGS *, char *, char *);
-DllExport char *Json_Object_Grp(UDF_INIT*, UDF_ARGS*, char*,
-                         unsigned long*, char *, char *);
+DllExport char *Json_Object_Grp(UDF_EXEC_ARGS);
 DllExport void Json_Object_Grp_clear(UDF_INIT *, char *, char *);
 DllExport void Json_Object_Grp_deinit(UDF_INIT*);
 } // extern "C"
@@ -405,6 +410,67 @@ void Json_Array_Add_deinit(UDF_INIT* initid)
 } // end of Json_Array_Add_deinit
 
 /***********************************************************************/
+/*  Add values to a Json array.                                        */
+/***********************************************************************/
+my_bool Json_Array_Delete_init(UDF_INIT *initid, UDF_ARGS *args, char *message)
+{
+  unsigned long reslen, memlen;
+
+  if (args->arg_count != 2) {
+    strcpy(message, "Json_Value_Delete must have 2 arguments");
+    return true;
+  } else if (!IsJson(args, 0)) {
+    strcpy(message, "Json_Value_Delete first argument must be a json item");
+    return true;
+  } else
+    CalcLen(args, false, reslen, memlen);
+
+  return JsonInit(initid, message, reslen, memlen);
+} // end of Json_Array_Delete_init
+
+char *Json_Array_Delete(UDF_INIT *initid, UDF_ARGS *args, char *result, 
+                unsigned long *res_length, char *is_null, char *error)
+{
+  char   *str;
+  int     n;
+  PJVAL   jvp;
+  PJAR    arp;
+  PGLOBAL g = (PGLOBAL)initid->ptr;
+
+  PlugSubSet(g, g->Sarea, g->Sarea_Size);
+  jvp = MakeValue(g, args, 0);
+
+  if (jvp->GetValType() != TYPE_JAR) {
+    push_warning(current_thd, Sql_condition::WARN_LEVEL_WARN, 0, 
+                 "First argument is not an array");
+    str = args->args[0];
+  } else if (args->arg_type[1] != INT_RESULT) {
+    push_warning(current_thd, Sql_condition::WARN_LEVEL_WARN, 0, 
+                 "Second argument is not an integer");
+    str = args->args[0];
+  } else {
+    n = *(int*)args->args[1];
+    arp = jvp->GetArray();
+    arp->DeleteValue(n - 1);
+    arp->InitArray(g);
+
+    if (!(str = Serialize(g, arp, NULL, 0))) {
+      str = strcpy(result, g->Message);
+      push_warning(current_thd, Sql_condition::WARN_LEVEL_WARN, 0, str);
+      } // endif str
+
+  } // endif's
+
+  *res_length = strlen(str);
+  return str;
+} // end of Json_Array_Delete
+
+void Json_Array_Delete_deinit(UDF_INIT* initid)
+{
+  PlugExit((PGLOBAL)initid->ptr);
+} // end of Json_Array_Delete_deinit
+
+/***********************************************************************/
 /*  Make a Json Oject containing all the parameters.                   */
 /***********************************************************************/
 my_bool Json_Object_init(UDF_INIT *initid, UDF_ARGS *args, char *message)
diff --git a/storage/connect/mysql-test/connect/r/xml_html.result b/storage/connect/mysql-test/connect/r/xml_html.result
new file mode 100644
index 00000000000..7b5e0febe6e
--- /dev/null
+++ b/storage/connect/mysql-test/connect/r/xml_html.result
@@ -0,0 +1,32 @@
+Warnings:
+Warning 1105  No file name. Table will use t1.xml
+SET NAMES utf8;
+#
+# Testing HTML like XML file
+#
+CREATE TABLE beers (
+`Name` CHAR(16) FIELD_FORMAT='brandName',
+`Origin` CHAR(16) FIELD_FORMAT='origin',
+`Description` CHAR(32) FIELD_FORMAT='details')
+ENGINE=CONNECT TABLE_TYPE=XML FILE_NAME='beers.xml'
+TABNAME='table' OPTION_LIST='xmlsup=libxml2,rownode=tr,colnode=td';
+SELECT * FROM beers;
+Name  Origin  Description
+Huntsman  Bath, UK  Wonderful hop, light alcohol
+Tuborg  Danmark In small bottles
+DROP TABLE beers;
+#
+# Testing HTML file
+#
+CREATE TABLE coffee (
+`Name` CHAR(16),
+`Cups` INT(8),
+`Type` CHAR(16),
+`Sugar` CHAR(4))
+ENGINE=CONNECT TABLE_TYPE=XML FILE_NAME='coffee.htm'
+TABNAME='TABLE' HEADER=1 OPTION_LIST='xmlsup=libxml2,Coltype=HTML';
+SELECT * FROM coffee;
+Name  Cups  Type  Sugar
+T. Sexton 10  Espresso  No
+J. Dinnen 5 Decaf Yes
+DROP TABLE coffee;
diff --git a/storage/connect/mysql-test/connect/std_data/beers.xml b/storage/connect/mysql-test/connect/std_data/beers.xml
new file mode 100644
index 00000000000..1abc77fe0f9
--- /dev/null
+++ b/storage/connect/mysql-test/connect/std_data/beers.xml
@@ -0,0 +1,16 @@
+<?xml version="1.0"?>
+<Beers>
+  <table>
+    <th><td>Name</td><td>Origin</td><td>Description</td></th>
+    <tr>
+      <td><brandName>Huntsman</brandName></td>
+      <td><origin>Bath, UK</origin></td>
+      <td><details>Wonderful hop, light alcohol</details></td>
+    </tr>
+    <tr>
+      <td><brandName>Tuborg</brandName></td>
+      <td><origin>Danmark</origin></td>
+      <td><details>In small bottles</details></td>
+    </tr>
+  </table>
+</Beers>
diff --git a/storage/connect/mysql-test/connect/std_data/coffee.htm b/storage/connect/mysql-test/connect/std_data/coffee.htm
new file mode 100644
index 00000000000..95a23d5c0ad
--- /dev/null
+++ b/storage/connect/mysql-test/connect/std_data/coffee.htm
@@ -0,0 +1,24 @@
+<TABLE summary="This table charts the number of cups of coffe
+                consumed by each senator, the type of coffee (decaf
+                or regular), and whether taken with sugar.">
+  <CAPTION>Cups of coffee consumed by each senator</CAPTION>
+  <TR>
+    <TH>Name</TH>
+    <TH>Cups</TH>
+    <TH>Type of Coffee</TH>
+    <TH>Sugar?</TH>
+  </TR>
+  <TR>
+    <TD>T. Sexton</TD>
+    <TD>10</TD>
+    <TD>Espresso</TD>
+    <TD>No</TD>
+  </TR>
+  <TR>
+    <TD>J. Dinnen</TD>
+    <TD>5</TD>
+    <TD>Decaf</TD>
+    <TD>Yes</TD>
+  </TR>
+</TABLE>
+
diff --git a/storage/connect/mysql-test/connect/t/xml_html.test b/storage/connect/mysql-test/connect/t/xml_html.test
new file mode 100644
index 00000000000..1c84b46ec38
--- /dev/null
+++ b/storage/connect/mysql-test/connect/t/xml_html.test
@@ -0,0 +1,39 @@
+--source have_libxml2.inc
+
+let $MYSQLD_DATADIR= `select @@datadir`;
+
+SET NAMES utf8;
+
+--copy_file $MTR_SUITE_DIR/std_data/beers.xml $MYSQLD_DATADIR/test/beers.xml
+--copy_file $MTR_SUITE_DIR/std_data/coffee.htm $MYSQLD_DATADIR/test/coffee.htm
+
+--echo #
+--echo # Testing HTML like XML file
+--echo #
+CREATE TABLE beers (
+`Name` CHAR(16) FIELD_FORMAT='brandName',
+`Origin` CHAR(16) FIELD_FORMAT='origin',
+`Description` CHAR(32) FIELD_FORMAT='details')
+ENGINE=CONNECT TABLE_TYPE=XML FILE_NAME='beers.xml'
+TABNAME='table' OPTION_LIST='xmlsup=libxml2,rownode=tr,colnode=td';
+SELECT * FROM beers;
+DROP TABLE beers;
+
+--echo #
+--echo # Testing HTML file
+--echo #
+CREATE TABLE coffee (
+`Name` CHAR(16),
+`Cups` INT(8),
+`Type` CHAR(16),
+`Sugar` CHAR(4))
+ENGINE=CONNECT TABLE_TYPE=XML FILE_NAME='coffee.htm'
+TABNAME='TABLE' HEADER=1 OPTION_LIST='xmlsup=libxml2,Coltype=HTML';
+SELECT * FROM coffee;
+DROP TABLE coffee;
+
+#
+# Clean up
+#
+--remove_file $MYSQLD_DATADIR/test/beers.xml
+--remove_file $MYSQLD_DATADIR/test/coffee.htm
diff --git a/storage/connect/tabxml.cpp b/storage/connect/tabxml.cpp
index 8ea44fed2be..1c1ff8a2ffe 100644
--- a/storage/connect/tabxml.cpp
+++ b/storage/connect/tabxml.cpp
@@ -1505,8 +1505,9 @@ bool XMLCOL::ParseXpath(PGLOBAL g, bool mode)
   } else if (Type == 2) {
     // HTML like table, columns are retrieved by position
     new(this) XPOSCOL(Value);        // Change the class of this column
-    Tdbp->Hasnod = true;
-    return false;
+    Inod = -1;
+//  Tdbp->Hasnod = true;
+//  return false;
   } else if (Type == 0 && !mode) {
     strcat(strcat(pbuf, "@"), Name);
   } else {                           // Type == 1