MDEV-3816 init-file stops getting executed if a long enough line is encountered; on a debug version, assertion `! is_set() || can_overwrite_status' fails

backport improved bootstrap error handling from 5.6

Was:
  revno: 3768.1.1
  committer: Christopher Powers <chris.powers@oracle.com>
  timestamp: Wed 2012-05-02 22:16:40 -0500
  message:
    Bug#11766342 INITIAL DB CREATION FAILS ON WINDOWS WITH AN ASSERT IN SQL_ERROR.CC
    Improved bootstrap error handling:
    - Detect and report file i/o errors
    - Report query size errors with nearest query text

mysql-test/r/init_file_longline_3816.result

@@ -0,0 +1,3 @@
+select count(*) from t4;
+count(*)
+0

mysql-test/t/init_file_longline_3816.opt

@@ -0,0 +1 @@
+--init-file=$MYSQL_TEST_DIR/std_data/init_file_longline_3816.sql

mysql-test/t/init_file_longline_3816.test

@@ -0,0 +1,5 @@
+#
+# MDEV-3816 init-file stops getting executed if a long enough line is encountered; on a debug version, assertion `! is_set() || can_overwrite_status' fails
+#
+select count(*) from t4;
+

scripts/comp_sql.c

@@ -65,9 +65,12 @@ static void die(const char *fmt, ...)
   exit(1);
 }
 
-char *fgets_fn(char *buffer, size_t size, fgets_input_t input)
+char *fgets_fn(char *buffer, size_t size, fgets_input_t input, int *error)
 {
-  return fgets(buffer, size, (FILE*) input);
+  char *line= fgets(buffer, size, (FILE*) input);
+  if (error)
+    *error= (line == NULL) ? ferror((FILE*)input) : 0;
+  return line;
 }
 
 static void print_query(FILE *out, const char *query)
@@ -116,6 +119,8 @@ int main(int argc, char *argv[])
   char* outfile_name= argv[3];
   int rc;
   int query_length;
+  int error= 0;
+  char *err_ptr;
 
   if (argc != 4)
     die("Usage: comp_sql <struct_name> <sql_filename> <c_filename>");
@@ -136,14 +141,34 @@ int main(int argc, char *argv[])
   for ( ; ; )
   {
     rc= read_bootstrap_query(query, &query_length,
-                             (fgets_input_t) in, fgets_fn);
-
-    if (rc == READ_BOOTSTRAP_ERROR)
-      die("Failed to read the bootstrap input file.\n");
+                             (fgets_input_t) in, fgets_fn, &error);
 
     if (rc == READ_BOOTSTRAP_EOF)
       break;
 
+    if (rc != READ_BOOTSTRAP_SUCCESS)
+    {
+      /* Get the most recent query text for reference. */
+      err_ptr= query + (query_length <= MAX_BOOTSTRAP_ERROR_LEN ?
+                                 0 : (query_length - MAX_BOOTSTRAP_ERROR_LEN));
+      switch (rc)
+      {
+      case READ_BOOTSTRAP_ERROR:
+        die("Failed to read the bootstrap input file. Return code (%d).\n"
+            "Last query: '%s'\n", error, err_ptr);
+        break;
+
+      case READ_BOOTSTRAP_QUERY_SIZE:
+        die("Failed to read the boostrap input file. Query size exceeded %d bytes.\n"
+            "Last query: '%s'.\n", MAX_BOOTSTRAP_LINE_SIZE, err_ptr);
+        break;
+    
+      default:
+        die("Failed to read the boostrap input file. Unknown error.\n");
+        break;
+      }
+    }
+
     print_query(out, query);
   }
 

sql/sql_bootstrap.cc

@@ -14,24 +14,34 @@
    51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA */
 
 
+#include <stdlib.h>
+#include <errno.h>
 #include <ctype.h>
 #include <string.h>
 #include "sql_bootstrap.h"
 
 int read_bootstrap_query(char *query, int *query_length,
-                         fgets_input_t input, fgets_fn_t fgets_fn)
+                         fgets_input_t input, fgets_fn_t fgets_fn, int *error)
 {
   char line_buffer[MAX_BOOTSTRAP_LINE_SIZE];
   const char *line;
   int len;
   int query_len= 0;
+  int fgets_error= 0;
+  *error= 0;
 
   for ( ; ; )
   {
-    line= (*fgets_fn)(line_buffer, sizeof(line_buffer), input);
+    line= (*fgets_fn)(line_buffer, sizeof(line_buffer), input, &fgets_error);
+    
+    if (error)
+      *error= fgets_error;
+
+    if (fgets_error != 0)
+      return READ_BOOTSTRAP_ERROR;
       
     if (line == NULL)
-      return (query_len ? READ_BOOTSTRAP_ERROR : READ_BOOTSTRAP_EOF);
+      return (query_len == 0) ? READ_BOOTSTRAP_EOF : READ_BOOTSTRAP_ERROR;
 
     len= strlen(line);
 
@@ -67,10 +77,22 @@ int read_bootstrap_query(char *query, int *query_length,
     if (strncmp(line, "delimiter", 9) == 0)
       continue;
 
-    /* Append the current line to a multi line query. */
-
+    /* Append the current line to a multi line query. If the new line will make
+       the query too long, preserve the partial line to provide context for the
+       error message.
+    */
     if (query_len + len + 1 >= MAX_BOOTSTRAP_QUERY_SIZE)
-      return READ_BOOTSTRAP_ERROR;
+    {
+      int new_len= MAX_BOOTSTRAP_QUERY_SIZE - query_len - 1;
+      if ((new_len > 0) && (query_len < MAX_BOOTSTRAP_QUERY_SIZE))
+      {
+        memcpy(query + query_len, line, new_len);
+        query_len+= new_len;
+      }
+      query[query_len]= '\0';
+      *query_length= query_len;
+      return READ_BOOTSTRAP_QUERY_SIZE;
+    }
 
     if (query_len != 0)
     {
@@ -78,8 +100,7 @@ int read_bootstrap_query(char *query, int *query_length,
         Append a \n to the current line, if any,
         to preserve the intended presentation.
        */
-      query[query_len]= '\n';
-      query_len++;
+      query[query_len++]= '\n';
     }
     memcpy(query + query_len, line, len);
     query_len+= len;
@@ -92,7 +113,7 @@ int read_bootstrap_query(char *query, int *query_length,
       */
       query[query_len]= '\0';
       *query_length= query_len;
-      return 0;
+      return READ_BOOTSTRAP_SUCCESS;
     }
   }
 }

sql/sql_bootstrap.h

@@ -29,15 +29,18 @@
   Do not increase this size, use the multiline syntax instead.
 */
 #define MAX_BOOTSTRAP_LINE_SIZE 20000
+#define MAX_BOOTSTRAP_ERROR_LEN 256
 
+#define READ_BOOTSTRAP_SUCCESS     0
 #define READ_BOOTSTRAP_EOF         1
 #define READ_BOOTSTRAP_ERROR       2
+#define READ_BOOTSTRAP_QUERY_SIZE  3
 
 typedef void *fgets_input_t;
-typedef char * (*fgets_fn_t)(char *, size_t, fgets_input_t);
+typedef char * (*fgets_fn_t)(char *, size_t, fgets_input_t, int *error);
 
 int read_bootstrap_query(char *query, int *query_length,
-                         fgets_input_t input, fgets_fn_t fgets_fn);
+                         fgets_input_t input, fgets_fn_t fgets_fn, int *error);
 
 #endif
 

sql/sql_parse.cc

@@ -634,10 +634,13 @@ void execute_init_command(THD *thd, LEX_STRING *init_command,
 }
 
 
-static char *fgets_fn(char *buffer, size_t size, fgets_input_t input)
+static char *fgets_fn(char *buffer, size_t size, fgets_input_t input, int *error)
 {
   MYSQL_FILE *in= static_cast<MYSQL_FILE*> (input);
-  return mysql_file_fgets(buffer, size, in);
+  char *line= mysql_file_fgets(buffer, size, in);
+  if (error)
+    *error= (line == NULL) ? ferror(in->m_file) : 0;
+  return line;
 }
 
 
@@ -664,25 +667,53 @@ static void handle_bootstrap_impl(THD *thd)
 
   for ( ; ; )
   {
-    char buffer[MAX_BOOTSTRAP_QUERY_SIZE];
+    char buffer[MAX_BOOTSTRAP_QUERY_SIZE] = "";
     int rc, length;
     char *query;
+    int error= 0;
 
-    rc= read_bootstrap_query(buffer, &length, file, fgets_fn);
+    rc= read_bootstrap_query(buffer, &length, file, fgets_fn, &error);
 
-    if (rc == READ_BOOTSTRAP_ERROR)
+    if (rc == READ_BOOTSTRAP_EOF)
+      break;
+    /*
+      Check for bootstrap file errors. SQL syntax errors will be
+      caught below.
+    */
+    if (rc != READ_BOOTSTRAP_SUCCESS)
     {
-      thd->raise_error(ER_SYNTAX_ERROR);
+      /*
+        mysql_parse() may have set a successful error status for the previous
+        query. We must clear the error status to report the bootstrap error.
+      */
+      thd->get_stmt_da()->reset_diagnostics_area();
+
+      /* Get the nearest query text for reference. */
+      char *err_ptr= buffer + (length <= MAX_BOOTSTRAP_ERROR_LEN ?
+                                        0 : (length - MAX_BOOTSTRAP_ERROR_LEN));
+      switch (rc)
+      {
+      case READ_BOOTSTRAP_ERROR:
+        my_printf_error(ER_UNKNOWN_ERROR, "Bootstrap file error, return code (%d). "
+                        "Nearest query: '%s'", MYF(0), error, err_ptr);
+        break;
+
+      case READ_BOOTSTRAP_QUERY_SIZE:
+        my_printf_error(ER_UNKNOWN_ERROR, "Boostrap file error. Query size "
+                        "exceeded %d bytes near '%s'.", MYF(0),
+                        MAX_BOOTSTRAP_LINE_SIZE, err_ptr);
+        break;
+
+      default:
+        DBUG_ASSERT(false);
+        break;
+      }
+
       thd->protocol->end_statement();
       bootstrap_error= 1;
       break;
     }
 
-    if (rc == READ_BOOTSTRAP_EOF)
-      break;
-
-    DBUG_ASSERT(rc == 0);
-
     query= (char *) thd->memdup_w_gap(buffer, length + 1,
                                       thd->db_length + 1 +
                                       QUERY_CACHE_DB_LENGTH_SIZE +