Segfault in program "Name" when input is p1 as affine cryst group on right

[kiryph]

❯ cat ~/p1-group-right
#2
3
1 0 0
0 1 0
1 0 1
3
1 0 0
0 1 0
0 1 1

❯ ./bin/Name ~/p1-group-right
[1]    46017 segmentation fault  ./bin/Name ~/p1-group-right

p1 given as as space group on left still does not work. However, the program does not segfault but returns the error error in coboundary:

❯ cat ~/p1-group-left
#2
3
1 0 1
0 1 0
0 0 1
3
1 0 0
0 1 1
0 0 1

❯ ./bin/Name ~/p1-group-left
error in coboundary

The program works fine for p2, ... and other plane groups:

❯ cat ~/p2-group-right
#3
3
-1 0 0
0 -1 0
0 0 1
3
1 0 0
0 1 0
1 0 1
3
1 0 0
0 1 0
0 1 1

❯ ./bin/Name ~/p2-group-right
qname: group.1 zname: 1 1 aff_name: 0

Carat Version

Carat is compiled from github with latest commits:

❯ git log -n 2
commit 21bfdb516cc21c8e634a9fc99c469a07b8c7490c (HEAD -> master, origin/master, origin/HEAD)
Author: Jerry James <[email protected]>
Date:   Mon Aug 15 13:18:53 2022 -0600

    Avoid a use after free

commit fd0b757974c491203e050912c09ac0bd504c7700
Author: Max Horn <[email protected]>
Date:   Sun Oct 17 21:00:09 2021 +0200

    Improve setup_carat_location on macOS

    The macro SYS_IS_DARWIN is only valid in GAP, so this code was never used before

---

Backtrace with lldb

❯ lldb ./bin/Name ~/p1-group-right
(lldb) target create "./bin/Name"
Current executable set to '/Users/kiryph/.local/stow/carat/bin/Name' (x86_64).
(lldb) settings set -- target.run-args  "/Users/kiryph/p1-group-right"
(lldb) r
Process 47344 launched: '/Users/kiryph/.local/stow/carat/bin/Name' (x86_64)
Process 47344 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x4)
    frame #0: 0x00000001002cedb5 libgmp.10.dylib`__gmpz_mul + 34
libgmp.10.dylib`:
->  0x1002cedb5 <+34>: movslq 0x4(%rsi), %rax
    0x1002cedb9 <+38>: movq   %rax, %rcx
    0x1002cedbc <+41>: negq   %rcx
    0x1002cedbf <+44>: cmovlq %rax, %rcx
Target 0: (Name) stopped.
(lldb) bt
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x4)
  * frame #0: 0x00000001002cedb5 libgmp.10.dylib`__gmpz_mul + 34
    frame #1: 0x0000000100035b19 Name`MP_solve_mat(M=0x0000600000004fa0, rows=<unavailable>, cols=<unavailable>, B=0x0000600000004a30, Bcols=<unavailable>, X1cols=0x00007ff7bfefd774, X0kgv=0x00007ff7bfefd730) at MP_solve.c:170:11 [opt]
    frame #2: 0x0000000100030d6e Name`long_solve_mat(A=0x0000600000c00d20, B=0x0000600000c00180) at long_solve_mat.c:47:8 [opt]
    frame #3: 0x000000010005b665 Name`coboundary(G=0x0000000100405180, C=0x0000600000c00180, T=0x0000600000c002d0) at coboundary.c:84:9 [opt]
    frame #4: 0x00000001000441cb Name`aff_class_inf(R=<unavailable>, DATAZ=0x0000000100405180, PRES=0x0000600000c003c0, aff_name=0x00007ff7bfefe8d8, RC=0x0000000000000000) at aff_class_inf.c:183:7 [opt]
    frame #5: 0x0000000100002fca Name`main(argc=<unavailable>, argv=<unavailable>) at name.c:0:9 [opt]
    frame #6: 0x000000010009552e dyld`start + 462
(lldb)

[kiryph]

Additional Debugging

Since the source code of CARAT contains debug output when setting INFO_LEVEL via the command line option -h, I observed a different code path with -h=4.

In order to allow -h=4, the source code for src/name.c must be modified:

diff --git a/src/name.c b/src/name.c
index 193d3e1..8d4873e 100644
--- a/src/name.c
+++ b/src/name.c
@@ -48,7 +48,7 @@ int main (int argc, char *argv[])
   if (is_option('h'))
     INFO_LEVEL = optionnumber('h');

-  if ((is_option('h') && INFO_LEVEL != 8) || FILEANZ == 0)
+  if ((is_option('h') && INFO_LEVEL == 0) || FILEANZ == 0)
     {
       printf("Usage: %s file [-T] [-Z] [-o] [-M] [-c]\n",argv[0]);
       printf("\n");

Again the program segfaults but at a different place:

lldb -- ./bin/Name ~/p1-group-right -h=4
(lldb) target create "./bin/Name"
Current executable set to '/Users/kiryph/.local/stow/carat/bin/Name' (x86_64).
(lldb) settings set -- target.run-args  "/Users/kiryph/p1-group-right" "-h=4"
(lldb) r
...
entering cong_solve
2d0	% loesungen[1]
1
2d0	% umform
1
2	% A
 1 0
 0 1
2d0	% loesungen[1]
1
2d0	% umform
1
2x0	% loesungen[0]


0	% loesungen[1]
2x0	% cozykel


0d0	% elementar
Process 79019 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x0)
    frame #0: 0x0000000100026dff Name`fput_mat(outfile=0x00007ff85c7e9998, mat=0x0000600000c0c1b0, comment="elementar", options=2) at put_mat.c:155:35
   152 	  if ( flags.Integral || Normalized ) {
   153 	    if ( flags.Diagonal ) {
   154 	      if ( flags.Scalar ) {
-> 155 	        fprintf (outfile, "%d\n", mat->array.SZ[0][0]);
   156 	      } else {
   157 	        for ( i  = 0 ; i < mat->rows; i++  ) {
   158 	          fprintf (outfile, "%d ", mat->array.SZ[i][i]);
Target 0: (Name) stopped.
(lldb) bt
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x0)
  * frame #0: 0x0000000100026dff Name`fput_mat(outfile=0x00007ff85c7e9998, mat=0x0000600000c0c1b0, comment="elementar", options=2) at put_mat.c:155:35
    frame #1: 0x0000000100026b2f Name`put_mat(mat=0x0000600000c0c1b0, file_name=0x0000000000000000, comment="elementar", options=2) at put_mat.c:74:3
    frame #2: 0x0000000100065111 Name`cohomology(dim=0x00007ff7bfefd7f8, mat=0x0000600000009260, matinv=0x000060000000c010, relator=0x000060000020c020, erzeuger=1, relatoren=1) at zass.c:400:8
    frame #3: 0x00000001000472c9 Name`aff_class_inf(R=0x00000001005046c0, DATAZ=0x0000000100504e40, PRES=0x0000600000c08360, aff_name=0x00007ff7bfefe8a8, RC=0x0000000000000000) at aff_class_inf.c:165:8
    frame #4: 0x000000010000192f Name`main(argc=3, argv=0x00007ff7bfefea60) at name.c:156:10
    frame #5: 0x00000001000a152e dyld`start + 462

Intermediate stdlog output is omitted.

This is strange. The debug level for additional output should not have an influence on the code path.