Backport BUG#25192 Using relay-log and relay-log-index without values produces unexpected results.

Options loaded from config files were added before command line
arguments, and they were parsed together, which could interprete
the following:
option-a
option-b
as --option-a=--option-b if 'option-a' requires a value, and 
caused confusing.

Because all options that requires a value are always given in
the form '--option=value', so it's an error if there is no 
'=value' part for such an option read from config file.

This patch added a separator to separate the arguments from 
config files and that from command line, so that they can be
handled differently. And report an error for options loaded
from config files that requires a value and is not given in the
form '--option=value'.

1 files changed, 37 insertions, 8 deletions

diff --git a/mysys/default.c b/mysys/default.c
index 1c021b4584f..c610b57c6d1 100644
--- a/mysys/default.c
+++ b/mysys/default.c
@@ -41,6 +41,29 @@
 #include <winbase.h>
 #endif
 
+/**
+   arguments separator
+
+   load_defaults() loads arguments from config file and put them
+   before the arguments from command line, this separator is used to
+   separate the arguments loaded from config file and arguments user
+   provided on command line.
+
+   Options with value loaded from config file are always in the form
+   '--option=value', while for command line options, the value can be
+   given as the next argument. Thus we used a separator so that
+   handle_options() can distinguish them.
+
+   Note: any other places that does not need to distinguish them
+   should skip the separator.
+
+   The content of arguments separator does not matter, one should only
+   check the pointer, use "----args-separator----" here to ease debug
+   if someone misused it.
+
+   See BUG#25192
+*/
+const char *args_separator= "----args-separator----";
 const char *my_defaults_file=0;
 const char *my_defaults_group_suffix=0;
 char *my_defaults_extra_file=0;
@@ -454,10 +477,11 @@ int my_load_defaults(const char *conf_file, const char **groups,
       goto err;
     res= (char**) (ptr+sizeof(alloc));
     res[0]= **argv;				/* Copy program name */
+    /* set arguments separator */
+    res[1]= args_separator;
     for (i=2 ; i < (uint) *argc ; i++)
-      res[i-1]=argv[0][i];
-    res[i-1]=0;					/* End pointer */
-    (*argc)--;
+      res[i]=argv[0][i];
+    res[i]=0;					/* End pointer */
     *argv=res;
     *(MEM_ROOT*) ptr= alloc;			/* Save alloc root for free */
     if (default_directories)
@@ -487,7 +511,7 @@ int my_load_defaults(const char *conf_file, const char **groups,
     or a forced default file
   */
   if (!(ptr=(char*) alloc_root(&alloc,sizeof(alloc)+
-			       (args.elements + *argc +1) *sizeof(char*))))
+			       (args.elements + *argc + 1 + 1) *sizeof(char*))))
     goto err;
   res= (char**) (ptr+sizeof(alloc));
 
@@ -508,12 +532,16 @@ int my_load_defaults(const char *conf_file, const char **groups,
     --*argc; ++*argv;				/* skip argument */
   }
 
+  /* set arguments separator for arguments from config file and
+     command line */
+  res[args.elements+1]= args_separator;
+
   if (*argc)
-    memcpy((uchar*) (res+1+args.elements), (char*) ((*argv)+1),
+    memcpy((uchar*) (res+1+args.elements+1), (char*) ((*argv)+1),
 	   (*argc-1)*sizeof(char*));
-  res[args.elements+ *argc]=0;			/* last null */
+  res[args.elements+ *argc+1]=0;                /* last null */
 
-  (*argc)+=args.elements;
+  (*argc)+=args.elements+1;
   *argv= (char**) res;
   *(MEM_ROOT*) ptr= alloc;			/* Save alloc root for free */
   delete_dynamic(&args);
@@ -523,7 +551,8 @@ int my_load_defaults(const char *conf_file, const char **groups,
     printf("%s would have been started with the following arguments:\n",
 	   **argv);
     for (i=1 ; i < *argc ; i++)
-      printf("%s ", (*argv)[i]);
+      if ((*argv)[i] != args_separator) /* skip arguments separator */
+        printf("%s ", (*argv)[i]);
     puts("");
     exit(0);
   }