standards‑compliant thread id string

MagickCore/thread-private.h

@@ -85,6 +85,30 @@ static inline MagickThreadType GetMagickThreadId(void)
 #endif
 }
 
+static inline void DecorateFilenameWithThreadId(const char *filename,
+  char *thread_filename)
+{
+  MagickThreadType
+    id;
+
+  char
+    thread_id[2*sizeof(id)+1];
+
+  ssize_t
+    i;
+
+  unsigned char
+    bytes[sizeof(id)];
+
+  id=GetMagickThreadId();
+  (void) memcpy(bytes,&id,sizeof(id));
+  for (i=0; i < (ssize_t) sizeof(bytes); i++)
+    (void) sprintf(thread_id+2*i,"%02x",bytes[i]);
+  thread_id[sizeof(thread_id)-1]='\0';
+  (void) FormatLocaleString(thread_filename,MagickPathExtent,"%s|%s",thread_id,
+    filename);
+}
+
 static inline size_t GetMagickThreadSignature(void)
 {
 #if defined(MAGICKCORE_THREAD_SUPPORT)

coders/coders-private.h

@@ -36,13 +36,6 @@ extern ModuleExport size_t \
 extern ModuleExport void \
   Unregister ## coder ## Image(void);
 
-static inline void DecorateFilenameWithThreadId(const char *filename,
-  char *thread_filename)
-{
-  (void) FormatLocaleString(thread_filename,MagickPathExtent,"%.20g|%s",
-    (double) GetMagickThreadId(),filename);
-}
-
 static inline ImageType IdentifyImageCoderType(const Image *image,
   ExceptionInfo *exception)
 {