"git fast-import" crashes parsing output from "fossil export --git"

"git fast-import" fails while trying to import the latest "Fossil" fossil-sources (it dog-foods its own source-code). Namely, the below pasted commands caused the crash report below them (I've trimmed irrelevant noise from the report for brevity). One of the tests included in Fossil uses example-files to test its handling of filenames with special characters - in this case an embedded newline in "abc[NEWLINE]def.txt" - and "git fast-import" causes the second part of that filename (post-newline) to spill over as the "command" on the next line of its input when transforming the "fossil export" output into usable input. Considering git can handle such filenames, I guess "git fast-import" not handling them counts as a bug - unless a design-decision was made to not be as rigorous for the sake of simplicity in the import protocol? Or is "fossil export" perhaps outputting the filename incorrectly for the "fast-import" protocol (maybe it needs some kind of quoting)?

* Commands which cause the crash:
----8<----
fossil clone https://www.fossil-scm.org/xfer fossil.fossil
git init fossil-git
cd fossil-git
fossil export --git ../fossil.fossil | git fast-import
----8<----

* The part of "fossil export" output which breaks "git fast-import":
----8<----
...

commit refs/heads/test-ticket-d17d6e5b17 mark :26782 committer jan.nijtmans <jan.nijtmans> 1353531216 +0000 data 82 Just commit some weird filenames, even one with a newline in it, to test the code. from :26779 M 100644 :427 :abc M 100644 :10049 abc def.txt M 100644 :427 str"i"ng.h M 100644 :427 str[ing.txt M 100644 :427 xyz<5.x

... ----8<----

Crash report [trimmed]:
----8<----
fast-import crash report:
    fast-import process: 23836
    parent process     : 23835
    at 2018-01-29 15:12:07 +0000

fatal: Unsupported command: def.txt

Most Recent Commands Before Crash
---------------------------------
  M 100644 :10003 src/tkt.c
  M 100644 :9992 src/update.c
  M 100644 :9838 src/wiki.c
  M 100644 :9986 src/wikiformat.c
  M 100644 :9995 src/xfer.c
  M 100644 :10007 src/th_main.c

  commit refs/heads/trunk
  mark :26772
  committer drh <drh> 1353449638 +0000
  data 115
  from :26770
  M 100644 :9981 src/attach.c
  M 100644 :10028 src/captcha.c
  M 100644 :10012 src/info.c
  M 100644 :9906 src/login.c
  M 100644 :9965 src/style.c
  M 100644 :10017 src/tkt.c
  M 100644 :10025 src/wiki.c

  commit refs/heads/th1Hooks
  mark :26773
  committer mistachkin <mistachkin> 1353449970 +0000
  data 48
  from :26771
  M 100644 :10008 src/main.c

  commit refs/heads/trunk
  mark :26774
  committer mistachkin <mistachkin> 1353450526 +0000
  data 70
  from :26772
  M 100644 :9245 src/captcha.c
  M 100644 :10030 src/login.c

  commit refs/heads/th1Hooks
  mark :26775
  committer mistachkin <mistachkin> 1353452400 +0000
  data 51
  from :26773
  M 100644 :10036 src/main.c

  commit refs/heads/trunk
  mark :26776
  committer drh <drh> 1353459061 +0000
  data 141
  from :26774
  M 100644 :10027 src/attach.c
  M 100644 :9833 src/captcha.c
  M 100644 :9904 src/setup.c
  M 100644 :10031 src/style.c
  M 100644 :10032 src/tkt.c
  M 100644 :10033 src/wiki.c

  commit refs/heads/trunk
  mark :26777
  committer drh <drh> 1353460136 +0000
  data 56
  from :26776
  M 100644 :10037 src/captcha.c

  commit refs/heads/ticket-d17d6e5b17
  mark :26778
  committer jan.nijtmans <jan.nijtmans> 1353489155 +0000
  data 80
  from :26767
  M 100644 :10019 src/file.c
  M 100644 :9846 src/rebuild.c
  M 100644 :9677 src/vfile.c

  commit refs/heads/ticket-d17d6e5b17
  mark :26779
  committer jan.nijtmans <jan.nijtmans> 1353489615 +0000
  data 41
  from :26778
  M 100644 :10043 src/file.c

  commit refs/heads/trunk
  mark :26780
  committer drh <drh> 1353510669 +0000
  data 64
  from :26777
  M 100644 :9850 src/encode.c
  M 100644 :10018 src/wikiformat.c

  commit refs/heads/trunk
  mark :26781
  committer drh <drh> 1353515283 +0000
  data 51
  from :26780
  M 100644 :10047 src/wikiformat.c

  commit refs/heads/test-ticket-d17d6e5b17
  mark :26782
  committer jan.nijtmans <jan.nijtmans> 1353531216 +0000
  data 82
  from :26779
  M 100644 :427 :abc
  M 100644 :10049 abc
* def.txt

Active Branch LRU
-----------------
    active_branches = 5 cur, 5 max

  pos  clock name
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   1)   4672 refs/heads/test-ticket-d17d6e5b17
   2)   4669 refs/heads/ticket-d17d6e5b17
   3)   4654 refs/heads/dbReOpenConfigAttach
   4)   4665 refs/heads/th1Hooks
   5)   4671 refs/heads/trunk

Inactive Branches ----------------- ...[loads of trimmed entries]...

Marks ----- ...[loads of trimmed entries]...

------------------- END OF CRASH REPORT ----8<----