BUG#11745230: 12133: MASTER.INDEX FILE KEEPS MYSQLD FROM STARTING IF

              BIN LOG HAS BEEN MOVED 

When moving the binary/relay log files from one location to
another and restarting the server with a different log-bin or
relay-log paths, would cause the startup process to abort. The
root cause was that the server would not be able to find the log
files because it would consider old paths for entries in the
index file instead of the new location.  What's even worse, the
relative paths would not be considered relative to the path
provided in log-bin and relay-log, but to mysql_data_dir.
      
We fix the cases where the server contains relative paths. When
the server is reading from the index file, it checks whether the
entry contains relative paths. If it does, we replace it with the
absolute path set in log-bin/relay-log option. Absolute paths
remain unchanged and the index must be manually edited to
consider the new log-bin and/or relay-log path (this should be
documented). This is a fix for a GA version, that does not break
behavior (that much).
      
For development versions, we should go with Zhenxing's approach 
that removes paths altogether from index files.

1 files changed, 62 insertions, 0 deletions

diff --git a/sql/log.h b/sql/log.h
index 481bd545960..2e9d308e5e5 100644
--- a/sql/log.h
+++ b/sql/log.h
@@ -715,4 +715,66 @@ char *make_log_name(char *buff, const char *name, const char* log_ext);
 extern MYSQL_PLUGIN_IMPORT MYSQL_BIN_LOG mysql_bin_log;
 extern LOGGER logger;
 
+
+/**
+  Turns a relative log binary log path into a full path, based on the
+  opt_bin_logname or opt_relay_logname.
+
+  @param from         The log name we want to make into an absolute path.
+  @param to           The buffer where to put the results of the 
+                      normalization.
+  @param is_relay_log Switch that makes is used inside to choose which
+                      option (opt_bin_logname or opt_relay_logname) to
+                      use when calculating the base path.
+
+  @returns true if a problem occurs, false otherwise.
+ */
+
+inline bool normalize_binlog_name(char *to, const char *from, bool is_relay_log)
+{
+  DBUG_ENTER("normalize_binlog_name");
+  bool error= false;
+  char buff[FN_REFLEN];
+  char *ptr= (char*) from;
+  char *opt_name= is_relay_log ? opt_relay_logname : opt_bin_logname;
+
+  DBUG_ASSERT(from);
+
+  /* opt_name is not null and not empty and from is a relative path */
+  if (opt_name && opt_name[0] && from && !test_if_hard_path(from))
+  {
+    // take the path from opt_name
+    // take the filename from from 
+    char log_dirpart[FN_REFLEN], log_dirname[FN_REFLEN];
+    size_t log_dirpart_len, log_dirname_len;
+    dirname_part(log_dirpart, opt_name, &log_dirpart_len);
+    dirname_part(log_dirname, from, &log_dirname_len);
+
+    /* log may be empty => relay-log or log-bin did not 
+        hold paths, just filename pattern */
+    if (log_dirpart_len > 0)
+    {
+      /* create the new path name */
+      if(fn_format(buff, from+log_dirname_len, log_dirpart, "",
+                   MYF(MY_UNPACK_FILENAME | MY_SAFE_PATH)) == NULL)
+      {
+        error= true;
+        goto end;
+      }
+
+      ptr= buff;
+    }
+  }
+
+  DBUG_ASSERT(ptr);
+
+  if (ptr)
+    strmake(to, ptr, strlen(ptr));
+
+end:
+  DBUG_RETURN(error);
+}
+
+
+
 #endif /* LOG_H */