Bug#20854 XML functions: wrong result in ExtractValue

mysql-test/r/xml.result:
  - Adding test case
  - Fixing error message
mysql-test/t/xml.test:
  Adding test case
sql/item_xmlfunc.cc:
  For grammar rules with loops like:
  
    AdditiveExpr ::= MultiplicativeExpr ('+' MultiplicativeExpr)*
  
  If we scanned scanned '+' and then met an error when parsing
  MultiplicativeExpr, then we should fully stop parsing - without
  trying to apply any other rules.
  
  Fix: add "error" member into MY_XPATH structure,
  and make my_xpath_parse_term() never return success
  as soon as error set.
strings/xml.c:
  Adding my_xml_ctype map for flags, indicating
  whether a character is a space character, is a
  valid identifier start character, is a valid
  identifier body character. Using this map to
  properly scan identifiers. Also, using this map
  to scan spaces faster (instead of strchr).

2 files changed, 43 insertions, 1 deletions

diff --git a/mysql-test/r/xml.result b/mysql-test/r/xml.result
index 780be01d7ce..efe7d14095d 100644
--- a/mysql-test/r/xml.result
+++ b/mysql-test/r/xml.result
@@ -570,7 +570,7 @@ select extractvalue('<a>a<b>B</b></a>','a|/b');
 extractvalue('<a>a<b>B</b></a>','a|/b')
 a
 select extractvalue('<a>A</a>','/<a>');
-ERROR HY000: XPATH syntax error: '<a>'
+ERROR HY000: XPATH error: comparison of two nodesets is not supported: '<a>'
 select extractvalue('<a><b>b</b><b!>b!</b!></a>','//b!');
 ERROR HY000: XPATH syntax error: '!'
 select extractvalue('<a>A<b>B<c>C</c></b></a>','/a/descendant::*');
@@ -710,3 +710,29 @@ Data
 select extractValue('<foo><foo.bar>Data</foo.bar><something>Otherdata</something></foo>','/foo/something');
 extractValue('<foo><foo.bar>Data</foo.bar><something>Otherdata</something></foo>','/foo/something')
 Otherdata
+select extractValue('<zot><tim0><01>10:39:15</01><02>140</02></tim0></zot>','/zot/tim0/02');
+ERROR HY000: XPATH syntax error: '02'
+select extractValue('<zot><tim0><01>10:39:15</01><02>140</02></tim0></zot>','//*');
+extractValue('<zot><tim0><01>10:39:15</01><02>140</02></tim0></zot>','//*')
+NULL
+Warnings:
+Warning	1512	Incorrect XML value: 'parse error at line 1 pos 13: unknown token unexpected (ident or '/' wanted)'
+select extractValue('<.>test</.>','//*');
+extractValue('<.>test</.>','//*')
+NULL
+Warnings:
+Warning	1512	Incorrect XML value: 'parse error at line 1 pos 2: unknown token unexpected (ident or '/' wanted)'
+select extractValue('<->test</->','//*');
+extractValue('<->test</->','//*')
+NULL
+Warnings:
+Warning	1512	Incorrect XML value: 'parse error at line 1 pos 2: unknown token unexpected (ident or '/' wanted)'
+select extractValue('<:>test</:>','//*');
+extractValue('<:>test</:>','//*')
+test
+select extractValue('<_>test</_>','//*');
+extractValue('<_>test</_>','//*')
+test
+select extractValue('<x.-_:>test</x.-_:>','//*');
+extractValue('<x.-_:>test</x.-_:>','//*')
+test
diff --git a/mysql-test/t/xml.test b/mysql-test/t/xml.test
index d510a61f04d..3347573b4b7 100644
--- a/mysql-test/t/xml.test
+++ b/mysql-test/t/xml.test
@@ -360,3 +360,19 @@ select extractValue('<ns:element xmlns:ns="myns">a</ns:element>','/ns:element/@x
 #
 select extractValue('<foo><foo.bar>Data</foo.bar><something>Otherdata</something></foo>','/foo/foo.bar');
 select extractValue('<foo><foo.bar>Data</foo.bar><something>Otherdata</something></foo>','/foo/something');
+
+#
+# Bug#20854 XML functions: wrong result in ExtractValue
+#
+--error 1105
+select extractValue('<zot><tim0><01>10:39:15</01><02>140</02></tim0></zot>','/zot/tim0/02');
+select extractValue('<zot><tim0><01>10:39:15</01><02>140</02></tim0></zot>','//*');
+# dot and dash are bad identtifier start character
+select extractValue('<.>test</.>','//*');
+select extractValue('<->test</->','//*');
+# semicolon is good identifier start character
+select extractValue('<:>test</:>','//*');
+# underscore is good identifier start character
+select extractValue('<_>test</_>','//*');
+# dot, dash, underscore and semicolon are good identifier middle characters
+select extractValue('<x.-_:>test</x.-_:>','//*');