+ ** We're trying to delete a header field (annotation )if the
+ ** delete flag is not -2 or less. A value greater than zero
+ ** means that we're deleting the nth header field that matches
+ ** the field (component) name. A value of zero means that
+ ** we're deleting the first field in which both the field name
+ ** matches the component name and the field body matches the text.
+ ** The text is matched in its entirety if it begins with a slash;
+ ** otherwise the text is matched against whatever portion of the
+ ** field body follows the last slash. This allows matching of
+ ** both absolute and relative path names. This is because this
+ ** functionality was added to support attachments. It might be
+ ** worth having a separate flag to indicate path name matching
+ ** to make it more general. A value of -1 means to delete all
+ ** matching fields.
+ */
+
+ if (delete >= -1) {
+ /* Get the length of the field name since we use it often. */
+ length = strlen(comp);
+
+ /*
+ ** Initialize the field counter. This is only used if
+ ** we're deleting by number.
+ */
+ count = 0;
+
+ /*
+ ** Copy lines from the input file to the temporary file
+ ** until we either find the one that we're looking
+ ** for (which we don't copy) or we reach the end of
+ ** the headers. Both a blank line and a line beginning
+ ** with a - terminate the headers so that we can handle
+ ** both drafts and RFC-2822 format messages.
+ */
+
+ do {
+ /*
+ ** Get a line from the input file, growing the
+ ** field buffer as needed. We do this so that
+ ** we can fit an entire line in the buffer making
+ ** it easy to do a string comparison on both the
+ ** field name and the field body which might be
+ ** a long path name.
+ */
+
+ for (n = 0, cp = field; (c = getc(fp)) != EOF; *cp++ = c) {
+ if (c == '\n' && (c = getc(fp)) != ' ' && c != '\t') {
+ ungetc(c, fp);
+ c = '\n';
+ break;
+ }
+
+ if (++n >= field_size - 1) {
+ field = (char *) mh_xrealloc((void *)field, field_size *= 2);
+
+ cp = field + n - 1;
+ }
+ }
+
+ /* NUL-terminate the field */
+ *cp = '\0';
+
+ /*
+ ** Check for a match on the field name. We delete
+ ** the line by not copying it to the temporary
+ ** file if
+ **
+ ** o The delete flag is 0, meaning that we're
+ ** going to delete the first matching
+ ** field, and the text is NULL meaning that
+ ** we don't care about the field body.
+ **
+ ** o The delete flag is 0, meaning that we're
+ ** going to delete the first matching
+ ** field, and the text begins with a / meaning
+ ** that we're looking for a full path name,
+ ** and the text matches the field body.
+ **
+ ** o The delete flag is 0, meaning that we're
+ ** going to delete the first matching
+ ** field, the text does not begin with a /
+ ** meaning that we're looking for the last
+ ** path name component, and the last path
+ ** name component matches the text.
+ **
+ ** o The delete flag is positive meaning that
+ ** we're going to delete the nth field
+ ** with a matching field name, and this is
+ ** the nth matching field name.
+ **
+ ** o The delete flag is -1 meaning that we're
+ ** going to delete all fields with a
+ ** matching field name.
+ */
+
+ if (strncasecmp(field, comp, length) == 0 && field[length] == ':') {
+ if (delete == 0) {
+ if (text == NULL)
+ break;
+
+ for (cp = field + length + 1; *cp == ' ' || *cp == '\t'; cp++)
+ ;
+
+ if (*text == '/') {
+ if (strcmp(cp, text) == 0)
+ break;
+ }
+ else {
+ if ((sp = strrchr(cp, '/')) != NULL)
+ cp = sp + 1;
+
+ if (strcmp(cp, text) == 0)
+ break;
+ }
+ }
+
+ else if (delete == -1)
+ continue;
+
+ else if (++count == delete)
+ break;
+ }
+
+ /*
+ ** This line wasn't a match so copy it to the
+ ** temporary file.
+ */
+
+ if ((n = fputs(field, tmp)) == EOF || (c == '\n' && fputc('\n', tmp) == EOF))
+ adios(NULL, "unable to write temporary file.");
+
+ } while (*field != '\0' && *field != '-');
+
+ /*
+ ** Get rid of the field buffer because we're done with it.
+ */
+
+ free((void *)field);
+
+ } else {
+ /*
+ ** Find the end of the headers before adding the
+ ** annotations if we're appending instead of the default
+ ** prepending. A special check for no headers is needed
+ ** if appending.
+ */
+
+ if (append) {
+ /*
+ ** Copy lines from the input file to the temporary
+ ** file until we reach the end of the headers.
+ */
+
+ if ((c = getc(fp)) == '\n')
+ rewind(fp);
+
+ else {
+ putc(c, tmp);
+
+ while ((c = getc(fp)) != EOF) {
+ putc(c, tmp);
+
+ if (c == '\n') {
+ ungetc(c = getc(fp), fp);
+
+ if (c == '\n' || c == '-')
+ break;
+ }
+ }
+ }