`etags' bug?

[Paul Pogonyshev <pogonyshev@gmx.net>]

It seems that behaviour of `etags' is broken.  In GNU Go
there is a special rule for harvesting tags in pattern
files.  It looks like this:

[paul@localhost patterns]$ etags --language none --regex '/^Pattern[ \t]+[a-zA-Z0-9]+/' aa_attackpats.db && cat TAGS


aa_attackpats.db,513
Pattern A171,2917
Pattern A282,2958
Pattern A392,3002
Pattern A4103,3037
Pattern A5114,3072
Pattern A6124,3108
Pattern A7137,3157
Pattern A8146,3210
Pattern A9155,3242
Pattern A10168,3291
Pattern A11177,3324
Pattern A12192,3382
Pattern A13209,3461
Pattern A14228,3539
Pattern A15244,3657
Pattern A16260,3761
Pattern A17278,3849
Pattern A18298,3974
Pattern A19318,4140
Pattern A20334,4259
Pattern A21350,4378
Pattern A22366,4476
Pattern A23384,4619
Pattern A24400,4744
Pattern A25414,4911


Fine, this is exactly what is needed.  Now, there are also C
files in this directory.  So, we collect tags in them too:

[paul@localhost patterns]$ etags --language none --regex '/^Pattern[ \t]+[a-zA-Z0-9]+/' aa_attackpats.db --language auto --no-regex transform.c && cat TAGS


aa_attackpats.db,227
A*A77,2939
??OO150,3230
OX163,3270
?XOXO181,3345
?XOXO187,3364
;safe_omove(*) && oplay_attack_either(*,A,B)240,3584
?XXXX249,3706
?AAAA255,3725
;!oplay_attack(*,e) && oplay_attack(*,a,C) && oplay_attack(315,4072


transform.c,179
int transformation[transformation29,1596
const int transformation2[transformation232,1682
transformation_init(61,2317
int spiral[spiral80,2691
build_spiral_order(107,3606


I believe `etags' didn't behave like this.  When I first wrote
the tag-harvesting code for patterns, it worked just fine.  Now
it generates corrupted stuff when followed by C files.

Does anyone have any idea of what's wrong?

Paul