Re: [PATCH] Support display name substitution in customheaders

after a quick read of the match, the extracted display name is not sanitize=
d, it should probably be=2E

the parser at quick glance seems fragile, what happen if the display name =
is "Doe, John"

Would be nice to get a bunch of tests to make sure everything works as exp=
ected=2E

also I don t think rfc 2047 is handled=2E

Best regards,
bapt


Le 29 mars 2026 10:13:54 GMT+02:00, Baptiste Daroussin <bapt@nours=2Eeu> a=
 =C3=A9crit=C2=A0:
>Thank you, I will have a look at it asap, and see integrate it if possibl=
e in 2=2E0=2E0 which I intend to release soon
>
>Best regards,
>Bapt
>
>
>March 27, 2026 at 7:14 PM, "Lumin Etherlight" <lumin+mlmmj@etherlight=2El=
ink mailto:lumin+mlmmj@etherlight=2Elink?to=3D%22Lumin%20Etherlight%22%20%3=
Clumin%2Bmlmmj%40etherlight=2Elink%3E > wrote:
>
>
>>=20
>> Allow substitution of the variable $postername$ for
>> the display name of the user=2E The display name is
>> extracted from the sender's From: header=2E If a name
>> is not found, then this variable is substituted for
>> user's address, i=2Ee=2E the same value as $posteraddr$=2E
>> Proper handling of comments, and quoted strings, in
>> the From: address is also included=2E
>>=20
>> This allows the following `customheaders' use-case:
>>=20
>>  From: $postername$ via Project-List <project-list@example=2Ecom>
>>=20
>> Which would render, for example, as:
>>=20
>>  From: John Doe via Project-List <project-list@example=2Ecom>
>>=20
>> For the user:
>>=20
>>  John Doe <john@example=2Ecom>=2E
>> ---
>>  AUTHORS | 1 +
>>  include/find_email_adr=2Eh | 1 +
>>  include/wrappers=2Eh | 2 +-
>>  src/do_all_the_voodoo_here=2Ec | 22 ++++++++++++---
>>  src/dumpfd2fd=2Ec | 14 +++++++++-
>>  src/find_email_adr=2Ec | 52 ++++++++++++++++++++++++++++++++++++
>>  6 files changed, 86 insertions(+), 6 deletions(-)
>>=20
>> diff --git a/AUTHORS b/AUTHORS
>> index be21ced=2E=2E9d9b7df 100644
>> --- a/AUTHORS
>> +++ b/AUTHORS
>> @@ -1,3 +1,4 @@
>>  Mads Martin Joergensen <mmj@mmj=2Edk>
>>  Morten K=2E Poulsen <morten@afdelingp=2Edk>
>>  Ben Schmidt <mail_ben_schmidt@yahoo=2Ecom=2Eau>
>> +Lumin Etherlight <lumin+mlmmj@etherlight=2Elink>
>> diff --git a/include/find_email_adr=2Eh b/include/find_email_adr=2Eh
>> index e5da89b=2E=2E707fdd6 100644
>> --- a/include/find_email_adr=2Eh
>> +++ b/include/find_email_adr=2Eh
>> @@ -27,5 +27,6 @@
>>  #include <stddef=2Eh>
>> =20
>>  strlist *find_email_adr(const char *str, strlist *retval);
>> +char *find_display_name(char *name);
>> =20
>>  #endif /* FIND_EMAIL_ADR_H */
>> diff --git a/include/wrappers=2Eh b/include/wrappers=2Eh
>> index 2953bd2=2E=2E5a2c144 100644
>> --- a/include/wrappers=2Eh
>> +++ b/include/wrappers=2Eh
>> @@ -31,6 +31,6 @@ ssize_t readn(int fd, void *vptr, size_t n);
>>  int random_int(void);
>>  int dumpfd2fd(int infd, int outfd);
>>  int copy_file(int infd, int outfd, size_t bufsiz);
>> -int process_headers(int infd, FILE *outf, const char *from);
>> +int process_headers(int infd, FILE *outf, const char *from, const char=
 *name);
>> =20
>>  #endif /* WRAPPERS_H */
>> diff --git a/src/do_all_the_voodoo_here=2Ec b/src/do_all_the_voodoo_her=
e=2Ec
>> index 13aeb74=2E=2E14214a8 100644
>> --- a/src/do_all_the_voodoo_here=2Ec
>> +++ b/src/do_all_the_voodoo_here=2Ec
>> @@ -80,6 +80,7 @@ int do_all_the_voodoo_here(int infd, int outfd, int h=
drfd, int footfd,
>>  char *hdrline, *unfolded, *unqp;
>>  strlist allunfoldeds =3D tll_init();
>>  char *posteraddr =3D NULL;
>> + char *postername =3D NULL;
>>  bool hdrsadded =3D false;
>>  bool subject_present =3D false;
>>  int dupfd =3D dup(infd);
>> @@ -111,9 +112,16 @@ int do_all_the_voodoo_here(int infd, int outfd, in=
t hdrfd, int footfd,
>>  if(hdrfd >=3D 0) {
>>  strlist fromemails =3D tll_init();
>>  if ( readhdrs[0]=2Evaluecount =3D=3D 1 ) {
>> - find_email_adr(readhdrs[0]=2Evalues[0], &fromemails);
>> - if (tll_length(fromemails) > 0)
>> + find_email_adr(readhdrs[0]=2Evalues[0], &fromemails);
>> + if (tll_length(fromemails) > 0) {
>>  posteraddr =3D xstrdup(tll_front(fromemails));
>> + postername =3D find_display_name(readhdrs[0]=2Evalues[0]);
>> + if (!postername) {
>> + postername =3D posteraddr ?
>> + xstrdup(posteraddr) :
>> + xcalloc(1, 1);
>> + }
>> + }
>>  }
>>  tll_free_and_free(fromemails, free);
>>  }
>> @@ -129,12 +137,13 @@ int do_all_the_voodoo_here(int infd, int outfd, i=
nt hdrfd, int footfd,
>>  if(!hdrsadded &&
>>  ( strncasecmp(hdrline, "mime", 4) =3D=3D 0)) {
>>  if(hdrfd >=3D 0) {
>> - if(process_headers(hdrfd,outf,posteraddr ? posteraddr : "") < 0) {
>> + if(process_headers(hdrfd,outf,posteraddr ? posteraddr : "", posternam=
e ) < 0) {
>>  log_error(LOG_ARGS, "Could not "
>>  "add extra headers");
>>  free(unfolded);
>>  tll_free_and_free(allunfoldeds, free);
>>  free(posteraddr);
>> + free(postername);
>>  fclose(outf);
>>  fclose(f);
>>  return -1;
>> @@ -174,11 +183,12 @@ int do_all_the_voodoo_here(int infd, int outfd, i=
nt hdrfd, int footfd,
>> =20
>>  if(!hdrsadded ) {
>>  if(hdrfd >=3D 0) {
>> - if(process_headers(hdrfd,outf,posteraddr ? posteraddr : "") < 0) {
>> + if(process_headers(hdrfd,outf,posteraddr ? posteraddr : "", posternam=
e) < 0) {
>>  log_error(LOG_ARGS, "Could not "
>>  "add extra headers");
>>  tll_free_and_free(allunfoldeds, free);
>>  free(posteraddr);
>> + free(postername);
>>  fclose(outf);
>>  fclose(f);
>>  return -1;
>> @@ -195,6 +205,7 @@ int do_all_the_voodoo_here(int infd, int outfd, int=
 hdrfd, int footfd,
>>  tll_free_and_free(allunfoldeds, free);
>>  log_error(LOG_ARGS, "Error writing hdrs=2E");
>>  free(posteraddr);
>> + free(postername);
>>  fclose(outf);
>>  fclose(f);
>>  return -1;
>> @@ -209,6 +220,7 @@ int do_all_the_voodoo_here(int infd, int outfd, int=
 hdrfd, int footfd,
>>  if(dumpfd2fd(infd, outfd) < 0) {
>>  log_error(LOG_ARGS, "Error when dumping rest of mail");
>>  free(posteraddr);
>> + free(postername);
>>  fclose(f);
>>  return -1;
>>  }
>> @@ -219,11 +231,13 @@ int do_all_the_voodoo_here(int infd, int outfd, i=
nt hdrfd, int footfd,
>>  if(dumpfd2fd(footfd, outfd) < 0) {
>>  log_error(LOG_ARGS, "Error when adding footer");
>>  free(posteraddr);
>> + free(postername);
>>  return -1;
>>  }
>> =20
>>  fsync(outfd);
>> =20
>>  free(posteraddr);
>> + free(postername);
>>  return 0;
>>  }
>> diff --git a/src/dumpfd2fd=2Ec b/src/dumpfd2fd=2Ec
>> index 674e2b0=2E=2E431bac2 100644
>> --- a/src/dumpfd2fd=2Ec
>> +++ b/src/dumpfd2fd=2Ec
>> @@ -84,7 +84,7 @@ int dumpfd2fd(int from, int to)
>>  return (r);
>>  }
>> =20
>> -int process_headers(int infd, FILE *outf, const char *from)
>> +int process_headers(int infd, FILE *outf, const char *from, const char=
 *name)
>>  {
>>  char *line =3D NULL, *p, *to_be_subst, *new_line;
>>  size_t linecap =3D 0;
>> @@ -120,6 +120,18 @@ int process_headers(int infd, FILE *outf, const ch=
ar *from)
>>  return -1;
>>  }
>>  free(new_line);
>> + } else if ((to_be_subst =3D strstr(p, "$postername$")) !=3D NULL) {
>> + *to_be_subst =3D '\0';
>> + to_be_subst +=3D 12;
>> + xasprintf(&new_line, "%s%s%s", p, name, to_be_subst);
>> + if (fprintf(outf, "%s", new_line) < 0) {
>> + log_error(LOG_ARGS, "Could not write headers");
>> + free(new_line);
>> + free(line);
>> + fclose(f);
>> + return -1;
>> + }
>> + free(new_line);
>>  } else {
>>  if (fprintf(outf, "%s", p) < 0) {
>>  log_error(LOG_ARGS, "Could not write headers");
>> diff --git a/src/find_email_adr=2Ec b/src/find_email_adr=2Ec
>> index 0830098=2E=2E77b7cef 100644
>> --- a/src/find_email_adr=2Ec
>> +++ b/src/find_email_adr=2Ec
>> @@ -239,3 +239,55 @@ oncemore:
>> =20
>>  return retstruct;
>>  }
>> +
>> +/* -------------------------------------------------------------------=
--------*\
>> + * Extract the display name of the first user,
>> + * removing comments, for example:
>> + *
>> + * for the input string:
>> + * "John (Amazing) Smith" <john=2Esmith@example=2Ecom>,
>> + * "Jane Doe" <jane=2Edoe@example=2Ecom
>> + *
>> + * returns: "John Smith"
>> +\* -------------------------------------------------------------------=
--------*/
>> +char *
>> +find_display_name (char *name)
>> +{
>> + char *p, *nbuf, c;
>> + int nbuf_len, saw_angled_brackets;
>> +
>> + if (!name) return NULL;
>> + nbuf =3D xmalloc(strlen(name));
>> + saw_angled_brackets =3D 0;
>> + nbuf_len =3D 0;
>> +
>> + for (p =3D name; (c =3D *p) !=3D '\0' && isspace(c); p++);
>> + while ((c =3D *p++) !=3D '\0') {
>> + switch (c) {
>> + case '(':
>> + p =3D skip_comment(p);
>> + /* -------------------------------*\
>> + * Copy at most one space in place
>> + * of the comment=2E Don't copy any
>> + * whitespace if we are still at
>> + * the beginning of the string=2E
>> + */
>> + if (nbuf_len > 0 && isspace(*p) &&
>> + !isspace(nbuf[nbuf_len-1])) {
>> + nbuf[nbuf_len++] =3D *p++;
>> + }
>> + while(isspace(*p)) p++;
>> + /* -------------------------------*/
>> + break;
>> + case '<': saw_angled_brackets =3D 1; goto finished;
>> + case ',': goto finished;
>> + default: nbuf[nbuf_len++] =3D c; break;
>> + }
>> + }
>> +
>> + finished:
>> + if (!saw_angled_brackets || nbuf_len =3D=3D 0) { free(nbuf); return N=
ULL; }
>> + for (p--, p--; (c =3D *p) && isspace(c); p--, nbuf_len--);
>> + nbuf[nbuf_len++] =3D '\0';
>> + return nbuf;
>> +}
>> --=20
>> 2=2E46=2E4
>>