Bugzilla

OK, I've looked into it a bit. The space is removed here:
https://searchfox.org/comm-central/rev/d0e849e295a3acdd98d3201ecb3bbff3b15007c6/mailnews/mime/src/mimemsg.cpp#158
```
      if (mime_typep(kid, (MimeObjectClass*)&mimeInlineTextPlainFlowedClass)) {
        // Remove any stuffed space.
        if (length > 0 && ' ' == *line) {
          line++;
          length--;
        }
        return kid->clazz->parse_line(line, length, kid);
```
Typically in f=f leading spaces, so-called "stuffing", are removed.

I'm really confused here since the message text doesn't even appear to be flowed. Flowed should have a space at the end, no? =20?
If I change your example to
```
Bug 1689804 - Problem with format=flowed during forward when CTE is=20
 QP: Spaces at beginning of the line are ignored.
```
then everything is fine. If you look at comment #1, TB 68 did end the line in =20, only to mess up below at polarizado=.

So what's the issue here? That the QP we produce is wrong or that it's right and we don't process it correctly?

OK, I've looked into it a bit. The space is removed here:
https://searchfox.org/comm-central/rev/d0e849e295a3acdd98d3201ecb3bbff3b15007c6/mailnews/mime/src/mimemsg.cpp#158
```
      if (mime_typep(kid, (MimeObjectClass*)&mimeInlineTextPlainFlowedClass)) {
        // Remove any stuffed space.
        if (length > 0 && ' ' == *line) {
          line++;
          length--;
        }
        return kid->clazz->parse_line(line, length, kid);
```
Typically in f=f leading spaces, so-called "stuffing", are removed.

I'm really confused here since the message text doesn't even appear to be flowed. Flowed should have a space at the end, no? =20?
If I change your example to
```
Bug 1689804 - Problem with format=flowed during forward when CTE is=20
 QP: Spaces at beginning of the line are ignored.
```
then everything is fine. If you look at comment #1, TB 68 did end the line in =20, only to mess up below at polarizado=.

So what's the issue here? That the QP we produce is wrong or that it's right and we don't process it correctly?

EDIT: I really don't have much of a clue about QP :-(