Manual-merge from 5.5-bugfixing.

1 files changed, 10 insertions, 3 deletions

diff --git a/sql/field.cc b/sql/field.cc
index ce1b1fc6eb0..e5cae9ea8e3 100644
--- a/sql/field.cc
+++ b/sql/field.cc
@@ -6327,10 +6327,13 @@ int Field_str::store(double nr)
   ASSERT_COLUMN_MARKED_FOR_WRITE;
   char buff[DOUBLE_TO_STRING_CONVERSION_BUFFER_SIZE];
   uint local_char_length= field_length / charset()->mbmaxlen;
-  size_t length;
-  my_bool error;
+  size_t length= 0;
+  my_bool error= (local_char_length == 0);
+
+  // my_gcvt() requires width > 0, and we may have a CHAR(0) column.
+  if (!error)
+    length= my_gcvt(nr, MY_GCVT_ARG_DOUBLE, local_char_length, buff, &error);
 
-  length= my_gcvt(nr, MY_GCVT_ARG_DOUBLE, local_char_length, buff, &error);
   if (error)
   {
     if (table->in_use->abort_on_warning)
@@ -8408,6 +8411,8 @@ uchar *Field_enum::pack(uchar *to, const uchar *from,
   default:
     DBUG_ASSERT(0);
   }
+  MY_ASSERT_UNREACHABLE();
+  DBUG_RETURN(NULL);
 }
 
 const uchar *Field_enum::unpack(uchar *to, const uchar *from,
@@ -8430,6 +8435,8 @@ const uchar *Field_enum::unpack(uchar *to, const uchar *from,
   default:
     DBUG_ASSERT(0);
   }
+  MY_ASSERT_UNREACHABLE();
+  DBUG_RETURN(NULL);
 }