Post-merge fix: header is used by the client API. Obvious in retrospect.

Also, update a few cases missed by the initial patch.

client/mysqltest.cc:
  Remove trailing comma.
include/my_alloc.h:
  Do not use wrapper.
include/mysql.h.pp:
  Update ABI file.
plugin/semisync/semisync_master.h:
  Initialize variable.
sql/debug_sync.cc:
  Use C linkage.

client/mysqltest.cc

@@ -87,7 +87,7 @@ enum {
   OPT_SKIP_SAFEMALLOC=OPT_MAX_CLIENT_OPTION,
   OPT_PS_PROTOCOL, OPT_SP_PROTOCOL, OPT_CURSOR_PROTOCOL, OPT_VIEW_PROTOCOL,
   OPT_MAX_CONNECT_RETRIES, OPT_MAX_CONNECTIONS, OPT_MARK_PROGRESS,
-  OPT_LOG_DIR, OPT_TAIL_LINES, OPT_RESULT_FORMAT_VERSION, 
+  OPT_LOG_DIR, OPT_TAIL_LINES, OPT_RESULT_FORMAT_VERSION
 };
 
 static int record= 0, opt_sleep= -1;

include/my_alloc.h

@@ -23,7 +23,9 @@
 #define ALLOC_MAX_BLOCK_TO_DROP			4096
 #define ALLOC_MAX_BLOCK_USAGE_BEFORE_DROP	10
 
-C_MODE_START
+#ifdef __cplusplus
+extern "C" {
+#endif
 
 typedef struct st_used_mem
 {				   /* struct for once_alloc (block) */
@@ -51,6 +53,8 @@ typedef struct st_mem_root
   void (*error_handler)(void);
 } MEM_ROOT;
 
-C_MODE_END
+#ifdef  __cplusplus
+}
+#endif
 
 #endif

include/mysql.h.pp

@@ -202,7 +202,6 @@ typedef unsigned int MYSQL_FIELD_OFFSET;
 typedef unsigned long long my_ulonglong;
 #include "typelib.h"
 #include "my_alloc.h"
-C_MODE_START
 typedef struct st_used_mem
 {
   struct st_used_mem *next;
@@ -220,7 +219,6 @@ typedef struct st_mem_root
   unsigned int first_block_usage;
   void (*error_handler)(void);
 } MEM_ROOT;
-C_MODE_END
 typedef struct st_typelib {
   unsigned int count;
   const char *name;

plugin/semisync/semisync_master.h

@@ -153,7 +153,7 @@ class TranxNodeAllocator
   int free_nodes_before(TranxNode* node)
   {
     Block *block;
-    Block *prev_block;
+    Block *prev_block= NULL;
 
     block= first_block;
     while (block != current_block->next)

sql/debug_sync.cc

@@ -387,6 +387,13 @@ static st_debug_sync_globals debug_sync_global; /* All globals in one object */
 */
 extern "C" void (*debug_sync_C_callback_ptr)(const char *, size_t);
 
+/**
+  Callbacks from C files.
+*/
+C_MODE_START
+static void debug_sync_C_callback(const char *, size_t);
+static int debug_sync_qsort_cmp(const void *, const void *);
+C_MODE_END
 
 /**
   Callback for debug sync, to be used by C files. See thr_lock.c for example.