* cygmagic: Add define name to warning.

* dcrt0.cc (_dll_crt0): Check for changes in child_info size.
(multiple_cygwin_problem): Avoid "proc" errors when testing.  Just assume new
cygwin proc.
* shared_info.h (mount_info): Add 'cb' element for sanity checks.
(shared_info): Ditto.
* child_info.h (child_info): Add fhandler_union_size element for sanity
checking.
* shared.cc (open_shared): Detect shared region size mismatch between parent
and child.
(shared_info::initialize): Detect shared region size mismatch with expectation.
(memory_Init): Ditto.
* sigproc.cc (init_child_info): Correctly set cb in passed structure.
* shared.cc (open_shared):

winsup/cygwin/shared_info.h

@@ -17,7 +17,6 @@ class mount_item
  public:
   /* FIXME: Nasty static allocation.  Need to have a heap in the shared
      area [with the user being able to configure at runtime the max size].  */
-
   /* Win32-style mounted partition source ("C:\foo\bar").
      native_path[0] == 0 for unused entries.  */
   char native_path[MAX_PATH];
@@ -42,7 +41,8 @@ class mount_item
 
 #define MOUNT_VERSION	27	// increment when mount table changes and
 #define MOUNT_VERSION_MAGIC CYGWIN_VERSION_MAGIC (MOUNT_MAGIC, MOUNT_VERSION)
-#define CURR_MOUNT_MAGIC 0xfe35
+#define CURR_MOUNT_MAGIC 0x41e0
+#define MOUNT_INFO_CB 16488
 
 class reg_key;
 
@@ -53,6 +53,7 @@ class mount_info
 {
  public:
   DWORD version;
+ unsigned cb;
   DWORD sys_mount_table_counter;
   int nmounts;
   mount_item mount[MAX_MOUNTS];
@@ -138,14 +139,17 @@ public:
 				  cygwin_version.api_minor)
 #define SHARED_VERSION_MAGIC CYGWIN_VERSION_MAGIC (SHARED_MAGIC, SHARED_VERSION)
 
-#define CURR_SHARED_MAGIC 0x6f6e
+#define SHARED_INFO_CB 47112
+
+#define CURR_SHARED_MAGIC 0x88e
 
 /* NOTE: Do not make gratuitous changes to the names or organization of the
    below class.  The layout is checksummed to determine compatibility between
    different cygwin versions. */
 class shared_info
 {
-  DWORD inited;
+  DWORD version;
+  DWORD cb;
  public:
   int heap_chunk_in_mb;
   DWORD sys_mount_table_counter;