Fix for:

  bug #26215: mysql command line client should not strip comments
              from SQL statements
and
  bug #11230: Keeping comments when storing stored procedures

With the introduction of multiline comments support in the command line
client (mysql) in MySQL 4.1, it became impossible to preserve
client-side comments within single SQL statements or stored routines.
This feature was useful for monitoring tools and maintenance.

The patch adds a new option to the command line client
('--enable-comments', '-c') which allows to preserve SQL comments and
send them to the server for single SQL statements, and to keep comments
in the code for stored procedures / functions / triggers.

The patch is a modification of the contributed patch from bug #11230
with the following changes:
- code style changes to conform to the coding guidelines
- changed is_prefix() to my_strnncoll() to detect the DELIMITER
command, since the first one is case-sensitive and not charset-aware
- renamed t/comments-51.* to t/mysql_comments.*
- removed tests for comments in triggers since 5.0 does not have SHOW
CREATE TRIGGER (those tests will be added back in 5.1).

The test cases are only for bug #11230. No automated test case for bug
#26215 is possible due to the test suite deficiencies (though the cases
from the bug report were tested manually).


client/mysql.cc:
  Applied the contributed patch from bug11230 with the following changes:
  - code style changes to conform to the coding guidelines
  - changed is_prefix() to my_strnncoll() to detect the DELIMITER
  command, since the first one is case-sensitive and not charset-aware
  
  The patch adds a new option to the command line client which allows to
  preserve SQL comments and send them to the server to ensure better
  error reporting and to, keep comments in the code for stored procedures
  / functions / triggers.
mysql-test/r/mysql_comments.result:
  Added test cases for bug11230.
mysql-test/t/mysql_comments.sql:
  Added test cases for bug11230.
mysql-test/t/mysql_comments.test:
  Added test cases for bug11230.

1 files changed, 125 insertions, 43 deletions

diff --git a/client/mysql.cc b/client/mysql.cc
index 8e1b6c2a9b4..2c6d0df2274 100644
--- a/client/mysql.cc
+++ b/client/mysql.cc
@@ -140,6 +140,7 @@ static my_bool info_flag=0,ignore_errors=0,wait_flag=0,quick=0,
                default_pager_set= 0, opt_sigint_ignore= 0,
                show_warnings= 0;
 static volatile int executing_query= 0, interrupted_query= 0;
+static my_bool preserve_comments= 0;
 static ulong opt_max_allowed_packet, opt_net_buffer_length;
 static uint verbose=0,opt_silent=0,opt_mysql_port=0, opt_local_infile=0;
 static my_string opt_mysql_unix_port=0;
@@ -754,6 +755,10 @@ static struct my_option my_long_options[] =
   {"show-warnings", OPT_SHOW_WARNINGS, "Show warnings after every statement.",
     (gptr*) &show_warnings, (gptr*) &show_warnings, 0, GET_BOOL, NO_ARG, 
     0, 0, 0, 0, 0, 0},
+  {"comments", 'c', "Preserve comments. Send comments to the server."
+   " Comments are discarded by default, enable with --enable-comments",
+   (gptr*) &preserve_comments, (gptr*) &preserve_comments,
+   0, GET_BOOL, NO_ARG, 0, 0, 0, 0, 0, 0},
   { 0, 0, 0, 0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0}
 };
 
@@ -1131,10 +1136,6 @@ static int read_and_execute(bool interactive)
       status.exit_status=0;
       break;
     }
-    if (!in_string && (line[0] == '#' ||
-		       (line[0] == '-' && line[1] == '-') ||
-		       line[0] == 0))
-      continue;					// Skip comment lines
 
     /*
       Check if line is a mysql command line
@@ -1260,15 +1261,21 @@ static bool add_line(String &buffer,char *line,char *in_string,
 
   for (pos=out=line ; (inchar= (uchar) *pos) ; pos++)
   {
-    if (my_isspace(charset_info,inchar) && out == line && 
-        buffer.is_empty())
-      continue;
+    if (!preserve_comments)
+    {
+      // Skip spaces at the beggining of a statement
+      if (my_isspace(charset_info,inchar) && (out == line) &&
+          buffer.is_empty())
+        continue;
+    }
+        
 #ifdef USE_MB
+    // Accept multi-byte characters as-is
     int length;
     if (use_mb(charset_info) &&
         (length= my_ismbchar(charset_info, pos, end_of_line)))
     {
-      if (!*ml_comment)
+      if (!*ml_comment || preserve_comments)
       {
         while (length--)
           *out++ = *pos++;
@@ -1294,8 +1301,13 @@ static bool add_line(String &buffer,char *line,char *in_string,
       }
       if ((com=find_command(NullS,(char) inchar)))
       {
-        const String tmp(line,(uint) (out-line), charset_info);
-        buffer.append(tmp);
+        // Flush previously accepted characters
+        if (out != line)
+        {
+          buffer.append(line, (uint) (out-line));
+          out= line;
+        }
+        
         if ((*com->func)(&buffer,pos-1) > 0)
           DBUG_RETURN(1);                       // Quit
         if (com->takes_params)
@@ -1323,7 +1335,6 @@ static bool add_line(String &buffer,char *line,char *in_string,
               pos+= delimiter_length - 1; // Point at last delim char
           }
         }
-        out=line;
       }
       else
       {
@@ -1336,46 +1347,106 @@ static bool add_line(String &buffer,char *line,char *in_string,
       }
     }
     else if (!*ml_comment && !*in_string &&
-             (*pos == *delimiter && is_prefix(pos + 1, delimiter + 1) ||
-              buffer.length() == 0 && (out - line) >= 9 &&
-              !my_strcasecmp(charset_info, line, "delimiter")))
-    {					
-      uint old_delimiter_length= delimiter_length;
+             (out - line) >= 9 &&
+             !my_strnncoll(charset_info, (uchar*) pos, 9,
+                           (const uchar*) "delimiter", 9) &&
+             my_isspace(charset_info, pos[9]))
+    {
+      // Flush previously accepted characters
       if (out != line)
-	buffer.append(line, (uint) (out - line));	// Add this line
+      {
+        buffer.append(line, (uint32) (out - line));
+        out= line;
+      }
+
+      // Flush possible comments in the buffer
+      if (!buffer.is_empty())
+      {
+        if (com_go(&buffer, 0) > 0) // < 0 is not fatal
+          DBUG_RETURN(1);
+        buffer.length(0);
+      }
+
+      /*
+        Delimiter wants the get rest of the given line as argument to
+        allow one to change ';' to ';;' and back
+      */
+      buffer.append(pos);
+      if (com_delimiter(&buffer, pos) > 0)
+        DBUG_RETURN(1);
+
+      buffer.length(0);
+      break;
+    }
+    else if (!*ml_comment && !*in_string && is_prefix(pos, delimiter))
+    {
+      // Found a statement. Continue parsing after the delimiter
+      pos+= delimiter_length;
+
+      if (preserve_comments)
+      {
+        while (my_isspace(charset_info, *pos))
+          *out++= *pos++;
+      }
+      // Flush previously accepted characters
+      if (out != line)
+      {
+        buffer.append(line, (uint32) (out-line));
+        out= line;
+      }
+
+      if (preserve_comments && ((*pos == '#') ||
+                                ((*pos == '-') &&
+                                 (pos[1] == '-') &&
+                                 my_isspace(charset_info, pos[2]))))
+      {
+        // Add trailing single line comments to this statement
+        buffer.append(pos);
+        pos+= strlen(pos);
+      }
+
+      pos--;
+
       if ((com= find_command(buffer.c_ptr(), 0)))
       {
-        if (com->func == com_delimiter)
-        {
-          /*
-            Delimiter wants the get rest of the given line as argument to
-            allow one to change ';' to ';;' and back
-          */
-          char *end= strend(pos);
-          buffer.append(pos, (uint) (end - pos));
-          /* Ensure pos will point at \0 after the pos+= below */
-          pos= end - old_delimiter_length + 1;
-        }
-	if ((*com->func)(&buffer, buffer.c_ptr()) > 0)
-	  DBUG_RETURN(1);                       // Quit
+          
+        if ((*com->func)(&buffer, buffer.c_ptr()) > 0)
+          DBUG_RETURN(1);                       // Quit 
       }
       else
       {
-	if (com_go(&buffer, 0) > 0)             // < 0 is not fatal
-	  DBUG_RETURN(1);
+        if (com_go(&buffer, 0) > 0)             // < 0 is not fatal
+          DBUG_RETURN(1);
       }
       buffer.length(0);
-      out= line;
-      pos+= old_delimiter_length - 1;
     }
     else if (!*ml_comment && (!*in_string && (inchar == '#' ||
 			      inchar == '-' && pos[1] == '-' &&
 			      my_isspace(charset_info,pos[2]))))
-      break;					// comment to end of line
+    {
+      // Flush previously accepted characters
+      if (out != line)
+      {
+        buffer.append(line, (uint32) (out - line));
+        out= line;
+      }
+
+      // comment to end of line
+      if (preserve_comments)
+        buffer.append(pos);
+
+      break;
+    }
     else if (!*in_string && inchar == '/' && *(pos+1) == '*' &&
 	     *(pos+2) != '!')
     {
-      pos++;
+      if (preserve_comments)
+      {
+        *out++= *pos++;                       // copy '/'
+        *out++= *pos;                         // copy '*'
+      }
+      else
+        pos++;
       *ml_comment= 1;
       if (out != line)
       {
@@ -1385,8 +1456,21 @@ static bool add_line(String &buffer,char *line,char *in_string,
     }
     else if (*ml_comment && !ss_comment && inchar == '*' && *(pos + 1) == '/')
     {
-      pos++;
+      if (preserve_comments)
+      {
+        *out++= *pos++;                       // copy '*'
+        *out++= *pos;                         // copy '/'
+      }
+      else
+        pos++;
       *ml_comment= 0;
+      if (out != line)
+      {
+        buffer.append(line, (uint32) (out - line));
+        out= line;
+      }
+      // Consumed a 2 chars or more, and will add 1 at most,
+      // so using the 'line' buffer to edit data in place is ok.
       need_space= 1;
     }      
     else
@@ -1401,14 +1485,12 @@ static bool add_line(String &buffer,char *line,char *in_string,
       else if (!*ml_comment && !*in_string &&
 	       (inchar == '\'' || inchar == '"' || inchar == '`'))
 	*in_string= (char) inchar;
-      if (!*ml_comment)
+      if (!*ml_comment || preserve_comments)
       {
         if (need_space && !my_isspace(charset_info, (char)inchar))
-        {
           *out++= ' ';
-          need_space= 0;
-        }
-	*out++= (char) inchar;
+        need_space= 0;
+        *out++= (char) inchar;
       }
     }
   }
@@ -1418,7 +1500,7 @@ static bool add_line(String &buffer,char *line,char *in_string,
     uint length=(uint) (out-line);
     if (buffer.length() + length >= buffer.alloced_length())
       buffer.realloc(buffer.length()+length+IO_SIZE);
-    if (!(*ml_comment) && buffer.append(line,length))
+    if ((!*ml_comment || preserve_comments) && buffer.append(line, length))
       DBUG_RETURN(1);
   }
   DBUG_RETURN(0);