Cleanup xref table at exit of program (not after check), or when new file

[gedcom-parse.git] / gedcom / encoding.c

diff --git a/gedcom/encoding.c b/gedcom/encoding.c
index 9e4e9199561ca0778914aedf7ed89dff227d7628..315b4adfe425e83c4bc8e1ea310551074e702a94 100644 (file)
--- a/gedcom/encoding.c
+++ b/gedcom/encoding.c
@@ -102,6 +102,25 @@ void cleanup_encodings()
 /* Let function be called before main() */
 void update_gconv_search_path() __attribute__ ((constructor));
 
+/* Note:
+
+   The environment variable GCONV_PATH has to be adjusted before the very
+   first call of iconv_open.  For the most general case, it means that we
+   have to make our own constructor here (in case some of the other library
+   constructors would use iconv_open).
+
+   However, it looks like a change of an environment variable in a constructor
+   doesn't always survive until the main() function.  This is the case if
+   the environment variable is a new one, for which there was no room yet
+   in the initial environment.  The initial environment is located on the
+   stack, but when variables are added, it is moved to the heap (to be able
+   to grow).  Now, the main function takes again the one from the stack, not
+   from the heap, so changes are lost.
+
+   For this, the function below will also be called in gedcom_init(), which
+   needs to be called as early as possible in the program.
+ */
+
 void update_gconv_search_path()
 {
   char *gconv_path;
@@ -214,9 +233,11 @@ void close_conv_to_internal()
 char* to_internal(char* str, size_t len,
                  char* output_buffer, size_t out_len)
 {
+  size_t res;
   size_t outsize = out_len;
   char *wrptr = output_buffer;
   char *rdptr = conv_buf;
+  char *retval = output_buffer;
   /* set up input buffer (concatenate to what was left previous time) */
   /* can't use strcpy, because possible null bytes from unicode */
   memcpy(conv_buf + conv_buf_size, str, len);
@@ -224,9 +245,18 @@ char* to_internal(char* str, size_t len,
   /* set up output buffer (empty it) */
   memset(output_buffer, 0, out_len);
   /* do the conversion */
-  iconv(cd_to_internal, &rdptr, &conv_buf_size, &wrptr, &outsize);
+  res = iconv(cd_to_internal, &rdptr, &conv_buf_size, &wrptr, &outsize);
+  if (res == (size_t)-1) {
+    if (errno == EILSEQ) {
+      /* restart from an empty state and return NULL */
+      iconv(cd_to_internal, NULL, NULL, NULL, NULL);
+      retval = NULL;
+      rdptr++;
+      conv_buf_size--;
+    }
+  }
   /* then shift what is left over to the head of the input buffer */
   memmove(conv_buf, rdptr, conv_buf_size);
   memset(conv_buf + conv_buf_size, 0, sizeof(conv_buf) - conv_buf_size);
-  return output_buffer;
+  return retval;
 }