Add support for unbounded message sizes.

1 files changed, 44 insertions, 5 deletions

diff --git a/hugin.c b/hugin.c
index 0543172..33a9947 100644
--- a/hugin.c
+++ b/hugin.c
@@ -351,12 +351,39 @@ static int hug_output_fd(int fd, const char *msg, int withdate)
   return 0;
 }
 
+// These functions returns how big a buffer is needed to "render" the arg list.
+static int vscprintf(const char *fmt, va_list va)
+{
+#ifdef WIN32
+  return _vscprintf(fmt, va);
+#else
+  return vsnprintf(NULL, 0, fmt, va);
+#endif
+}
+
+static int scprintf(const char *fmt, ...)
+{
+  int size;
+  va_list va;
+  va_start(va, fmt);
+  size = vscprintf(fmt, va);
+  va_end(va);
+
+  return size;
+}
+
+#define HDR_ARGS debug_class_str[(unsigned)cl], ch, func, line
+
 int __debug(const char *func, const int line,
             const enum __debug_class cl,
             const char *ch, const char *fmt, ...)
 {
   int result = 0;
   int sz;
+  char *buf = NULL;
+  int hdr_bufsz = 0;
+  int msg_bufsz = 0;
+  const char hdr_fmt[] = "%s:%s:%s:%d ";
 
   // NOTE: This must be identical to the debug_class_str in debug_filter.c
   const char * const debug_class_str[] =
@@ -372,13 +399,23 @@ int __debug(const char *func, const int line,
   // Generate message
   //
 
-  char buf[1024];
-  sz = snprintf(buf, sizeof(buf),
-                "%s:%s:%s:%d ",
-                debug_class_str[(unsigned)cl], ch, func, line);
+  // Get number of bytes needed for the buffer:
   va_list va;
   va_start(va, fmt);
-  sz += vsnprintf(buf + sz, sizeof(buf) - sz, fmt, va);
+
+  hdr_bufsz = scprintf(hdr_fmt, HDR_ARGS);
+  msg_bufsz = vscprintf(fmt, va);
+  if(hdr_bufsz < 0 || msg_bufsz < 0) return 1; // Bad format?
+
+  buf = (char*)malloc(hdr_bufsz + msg_bufsz + 1);
+  if(!buf) return 1; // Out of memory
+
+  sz = sprintf(buf, hdr_fmt, HDR_ARGS);
+  if(sz < 0) return 1; // Unknown error
+
+  sz = vsprintf(buf + sz, fmt, va);
+  if(sz < 0) return 1; // Unknown error
+
   va_end(va);
 
   //
@@ -412,6 +449,8 @@ done:
 #endif
   hug_mutex_unlock();
 
+  if(buf) free(buf);
+
   return result;
 }