Merge heikki@build.mysql.com:/home/bk/mysql-4.0

into hundin.mysql.fi:/home/heikki/mysql-4.0

2 files changed, 34 insertions, 4 deletions

diff --git a/client/mysql.cc b/client/mysql.cc
index 66a99bbdf75..8343543ba33 100644
--- a/client/mysql.cc
+++ b/client/mysql.cc
@@ -2351,13 +2351,16 @@ com_status(String *buffer __attribute__((unused)),
     MYSQL_RES *result;
     LINT_INIT(result);
     tee_fprintf(stdout, "\nConnection id:\t\t%lu\n",mysql_thread_id(&mysql));
-    if (!mysql_query(&mysql,"select DATABASE(),USER()") &&
+    if (!mysql_query(&mysql,"select DATABASE(), USER() limit 1") &&
 	(result=mysql_use_result(&mysql)))
     {
       MYSQL_ROW cur=mysql_fetch_row(result);
-      tee_fprintf(stdout, "Current database:\t%s\n", cur[0] ? cur[0] : "");
-      tee_fprintf(stdout, "Current user:\t\t%s\n",cur[1]);
-      (void) mysql_fetch_row(result);		// Read eof
+      if (cur)
+      {
+        tee_fprintf(stdout, "Current database:\t%s\n", cur[0] ? cur[0] : "");
+        tee_fprintf(stdout, "Current user:\t\t%s\n", cur[1]);
+      }
+      mysql_free_result(result);
     }
 #ifdef HAVE_OPENSSL
     if (mysql.net.vio && mysql.net.vio->ssl_arg &&
diff --git a/sql/field.cc b/sql/field.cc
index 946f5ed8621..aca1f8846f0 100644
--- a/sql/field.cc
+++ b/sql/field.cc
@@ -2332,6 +2332,33 @@ String *Field_double::val_str(String *val_buffer,
 
   if (dec >= NOT_FIXED_DEC)
   {
+    /*
+      Let's try to pretty print a floating point number. Here we use
+      '%-*.*g' conversion string:
+        '-' stands for left-padding with spaces, if such padding will take
+      place
+        '*' is a placeholder for the first argument, field_length, and
+      signifies minimal width of result string. If result is less than
+      field length it will be space-padded. Note, however, that we'll not
+      pass spaces to Field_string::store(const char *, ...), due to
+      strcend in the next line.
+        '.*' is a placeholder for DBL_DIG and defines maximum number of
+      significant digits in the result string. DBL_DIG is a hardware
+      specific C define for maximum number of decimal digits of a floating
+      point number, such that rounding to hardware floating point
+      representation and back to decimal will not lead to loss of
+      precision. I.e if DBL_DIG is 15, number 123456789111315 can be
+      represented as double without precision loss.  As one can judge from
+      this description, chosing DBL_DIG here is questionable, especially
+      because it introduces a system dependency.
+        'g' means that conversion will use [-]ddd.ddd (conventional) style,
+      and fall back to [-]d.ddde[+|i]ddd (scientific) style if there is no
+      enough space for all digits.
+      Maximum length of result string (not counting spaces) is (I guess)
+      DBL_DIG + 8, where 8 is 1 for sign, 1 for decimal point, 1 for
+      exponent sign, 1 for exponent, and 4 for exponent value.
+      XXX: why do we use space-padding and trim spaces in the next line?
+    */
     sprintf(to,"%-*.*g",(int) field_length,DBL_DIG,nr);
     to=strcend(to,' ');
   }