Bug #12762377 FOREIGN KEYS NOT CONSTRUCTED WHEN APOSTROPHES ARE

ESCAPED WITH BACKSLASH

Problem:

When the CREATE TABLE statement used COMMENTS with escape sequences like
'foo\'s', InnoDB did not parse is correctly when trying to extract the
foreign key information.  Because of this, the foreign keys specified
in the CREATE TABLE statement were not created.

Solution:

Make the InnoDB internal parser aware of escape sequences. 

rb#2457 approved by Kevin.

storage/innobase/dict/dict0dict.c

@@ -2872,14 +2872,27 @@ dict_scan_to(
 	const char*	string)	/*!< in: look for this */
 {
 	char	quote	= '\0';
+	ibool	escape	= FALSE;
 
 	for (; *ptr; ptr++) {
 		if (*ptr == quote) {
 			/* Closing quote character: do not look for
 			starting quote or the keyword. */
+
+			/* If the quote character is escaped by a
+			backslash, ignore it. */
+			if (escape) {
+				escape = FALSE;
+			} else {
 				quote = '\0';
+			}
 		} else if (quote) {
 			/* Within quotes: do nothing. */
+			if (escape) {
+				escape = FALSE;
+			} else if (*ptr == '\\') {
+				escape = TRUE;
+			}
 		} else if (*ptr == '`' || *ptr == '"' || *ptr == '\'') {
 			/* Starting quote: remember the quote character. */
 			quote = *ptr;
@@ -3265,6 +3278,11 @@ dict_strip_comments(
 	char*		ptr;
 	/* unclosed quote character (0 if none) */
 	char		quote	= 0;
+	ibool		escape = FALSE;
+
+	DBUG_ENTER("dict_strip_comments");
+
+	DBUG_PRINT("dict_strip_comments", ("%s", sql_string));
 
 	str = mem_alloc(sql_length + 1);
 
@@ -3279,16 +3297,29 @@ end_of_string:
 
 			ut_a(ptr <= str + sql_length);
 
-			return(str);
+			DBUG_PRINT("dict_strip_comments", ("%s", str));
+			DBUG_RETURN(str);
 		}
 
 		if (*sptr == quote) {
 			/* Closing quote character: do not look for
 			starting quote or comments. */
+
+			/* If the quote character is escaped by a
+			backslash, ignore it. */
+			if (escape) {
+				escape = FALSE;
+			} else {
 				quote = 0;
+			}
 		} else if (quote) {
 			/* Within quotes: do not look for
 			starting quotes or comments. */
+			if (escape) {
+				escape = FALSE;
+			} else if (*sptr == '\\') {
+				escape = TRUE;
+			}
 		} else if (*sptr == '"' || *sptr == '`' || *sptr == '\'') {
 			/* Starting quote: remember the quote character. */
 			quote = *sptr;