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24 commits

Author SHA1 Message Date
beedf8dced retreat: Rewrite automatic retreat code to fix its many bugs
Much of the retreat code duplicates navigate and march code.  Worse,
retreat's version is full of bugs:

* Land units can sometimes retreat when they couldn't march: while on
  the trading block (forbidden with march since 4.0.9), crewless
  (likewise since 4.0.0), kidnapped in a foreign sector (inconsistent
  since land units were added in Chainsaw 3), loaded on a ship
  (likewise) or a land unit (inconsistent since trains were added in
  4.0.0).

* Ships can retreat while on the trading block (forbidden with
  navigate since 4.0.9)

* Land units can't retreat into foreign sectors even though they could
  march there, namely when sector is allied or the land unit is a spy.
  They can march there since 4.0.0.

* Land units keep their fortification on retreat.  Has been that way
  since retreat was added in Chainsaw.

Then there's group retreat.  It's basically crazy:

* It triggers retreat for everyone in the same fleet or army, one
  after the other, regardless of retreat path, conditions (including
  group retreat), or even location.  The latter is quite abusable
  since retreats aren't interdicted.  Has been that way since retreat
  was added in Chainsaw.

* Group retreat fails to trigger when the originally retreating ship
  or land unit has no retreat path left when it's done.  Broken in
  commit b860123.

Finally, the reporting to the owner is sub-par:

* When a retreat is cut short by insufficient mobility or
  obstructions, its end sector isn't reported, leaving the player
  guessing.

* Non-retreats can be confusingly reported as retreat to the same
  sector.  Can happen when the retreat path starts with 'h' (obscure
  feature to suppress a single retreat), or when a group retreat
  includes a ship or land unit without retreat orders.

* Interaction with mines during retreat is reported before the retreat
  itself, which can be quite confusing.

* Sweeping landmines isn't reported at all.

* Much code and much bulletin text is dedicated to reporting what
  caused the retreat, even though it should be perfectly obvious.

Rewrite this on top of common navigate and march code.  Reuse of
common code fixes the "can retreat when it couldn't navigate/march"
and the "can't retreat into sectors it could navigate or march into"
bugs, and improves the reporting.

One special case isn't a bug fix but a rule change: mountains.  The
old code forbids that explicitly, and it's clearly intentional, if
undocumented.  The new code allows it by not doing anything special.

Turn group retreat into an actual group retreat: everyone in the same
fleet and sector with the the same retreat path and group retreat
condition joins the group.  The group retreats together, just like in
navigate and march.

Take care to always report the end sector.  When retreat is
impossible, report "can't retreat".  When retreat is partial, report
"and stays in X,Y".  When it's complete, report "stopped at X,Y".

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
2015-03-02 08:20:48 +01:00
5bc934fe25 tests/retreat: Test mission clearing more thoroughly
Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
2015-03-02 08:20:48 +01:00
c820b984c7 tests/retreat: Cover spies
This exposes yet another bug.  It's marked "BUG:" in the test input.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
2015-03-02 08:20:48 +01:00
891039d384 tests/retreat: Cover trains
This exposes yet another bug.  It's marked "BUG:" in the test input.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
2015-03-02 08:20:48 +01:00
7da0c919f1 tests/retreat: Cover canals
Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
2015-03-02 08:20:48 +01:00
5d346f4af1 tests/retreat: Cover ships and land units on sale
This exposes more bugs.  They're marked "BUG:" in the test input.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
2015-03-02 08:20:48 +01:00
cc8b92d555 Revert "retreat: Don't report a destroyed ship/land unit couldn't retreat"
This reverts commit df8a1ffc1b.

Because it breaks group retreat.  Trivial conflicts due to the removal
of option SAIL.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>

Conflicts:
	src/lib/subs/retreat.c
	tests/retreat/journal.log
2015-03-02 08:20:48 +01:00
32a6504a25 tests/retreat: Improve group retreat coverage
This exposes more bugs.  They're marked "BUG:" in the test input.  A
few bugs get masked, but I'll unmask them again in the next commit.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
2015-03-02 08:20:48 +01:00
36df559f33 tests/retreat: Put some targets in separate locations
To reduce coupling between test cases.

Lucky dice expose another bug.  It's marked "BUG:" in the test input.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
2015-03-02 08:20:48 +01:00
49de769470 tests/retreat: Drop unused minefields
Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
2015-03-02 08:20:48 +01:00
104bf6f777 tests/retreat: Clean up setup, improve comments
setup-POGO unintentionally gives dead ships, planes and land units
mobility, which makes them show up in final.xdump.  Rearrange to avoid
that, and for clarity.  While there, improve comments.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
2015-03-02 08:20:48 +01:00
0a012a3ed5 edit: Fix tech and range adjustment for edit p key 'T'
It sets the new type, then falls through to setting tech if the new
type requires more than the plane currently has.  Two problems with
that:

* If we fall through, the plane is invalid: it has less tech than
  required.  Its only use before it gets overwritten is pln_set_tech()
  calling pln_range_max() to find out whether the range is limited.
  Passes a negative number to log().  Not fatal, but pln_set_tech()'s
  range adjustment is unlikely to work.

* If we don't fall through, the range may still need adjustment,
  either up (to keep it unlimited if the new type has more range), or
  down (to keep it within the new type's shorter range).

Screwed up when the key was added in commit 6b0b6f17.  Fix by
adjusting tech first, then setting the type, then adjusting the range.
The latter relies on pln_set_tech() coping with ranges exceeding the
type's maximum, which it does.

Change the other type edits similarly for consistency.

When a type edit triggers a tech change, the tech change is now
silent.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
2015-03-02 08:20:47 +01:00
f9316f71c4 torpedo: Fix mobility cost of retreat after hit
torp() applies torpedo damage after retreat.  Wrong, because mobility
cost increases with damage.  Broken since retreat was added in
Chainsaw.

Fix by applying damage before retreat.  Bonus: bulletins make more
sense.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
2015-02-28 16:21:35 +01:00
dc73207a99 sail: Remove option SAIL
SAIL has issues:

* Sail orders are executed at the update.  Crafty players can use them
  to get around the update window.

* The route is fixed at command time.  You can't let the update find
  the best route, like it does for distribution.

* The info pages documenting it amount to almost 100 non-blank lines
  formatted.  They claim you can follow friendly ships.  This is
  wrong.  They also show incorrect follow syntax.  Unlikely to be the
  only errors.

* Few players use it.  Makes it a nice hidey-hole for bugs.  Here are
  two nice ones:

  - If follow's second argument is negative, the code attempts to
    follow an uninitialized ship.  Could well be a remote hole.

  - If ship #1 follows #2 follows #3 follows #2, the update goes into
    an infinite loop.

* It's more than 500 lines of rather crufty code nobody wants to
  touch.  Thanks to a big effort in Empire 2, it shares some code with
  the navigation command.  It still duplicates other navigation code.
  The sharing complicates fixing the bugs demonstrated by
  navi-march-test.

Reviewing, fixing and testing this mess isn't worth the opportunity
cost.  Remove it instead.  Drop commands follow, mquota, sail and
unsail.  Drop ship selectors mquota, path, follow.

struct shpstr shrinks some more, on my system from 160 to 120 bytes.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
2015-02-28 16:11:28 +01:00
48e656c057 autonav: Remove the feature
The autonavigation feature has issues:

* Autonavigation orders are executed at the update.  Crafty players
  can use them to get around the update window.

* Usability is poor:

  - The order command is overly complex, not least because it can do
    five different things: clear, suspend, resume, declare route, set
    cargo levels.

  - Unlike every other command involving movement, order does not let
    you specify routes, only destination sectors.

  - Setting cargo levels can silently swap start and end point of a
    circular route, because "this keeps the load_it() procedure
    happy".  Maybe it does, but it surely keeps players confused.

  - Setting "start" cargo levels actually sets the "end" levels, and
    vice versa.  Has always been broken that way.

  - Predicting what exactly autonavigation will do at the update isn't
    easy.

* The info pages documenting it amount to almost 400 non-blank lines
  formatted.  They claim only merchant ships can be given orders.
  This is wrong.  Unlikely to be the only error.

* Few players use it, and its workings at the update a fairly opaque.
  Makes it a nice hidey-hole for bugs.  Here are two:

  - Unlike the scuttle command, autonavigation happily scuttles trade
    ships while they're on the trading block.

  - Unlike the load command, autonavigation can load in friendly and
    allied sectors.

* It's more than 700 lines of rather crufty code nobody wants to
  touch.  Thanks to a big effort in Empire 2, it shares code with the
  navigation command.  It still duplicates load code.  The sharing
  complicates fixing the bugs demonstrated by navi-march-test.

Reviewing, fixing and testing this mess isn't worth the opportunity
cost.  Remove it instead.  Drop commands order, qorder and sorder.
Drop ship selectors xstart, xend, ystart, yend, cargostart, cargoend,
amtstart, amtend, autonav.

xdump ship sheds almost half its columns.  struct shpstr shrinks, on
my system from 200 to 160 bytes.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
2015-02-28 16:10:22 +01:00
f4f048234c empdump: Omit redundant data from export, new -c includes it
Cuts size of export files in test suite by a factor of four.  Not a
big deal for disk usage, as export files compress very well, and disk
space is cheap anyway.  Export files are simply easier to work with
when they aren't full of redundant crap.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
2015-02-01 16:53:00 +01:00
ff826d2582 retreat: Don't consume a retreat direction that wasn't followed
When a retreating ship or land unit runs into a sector it can't enter,
it stops.  The direction character that led it there is consumed, even
though it could not be followed.  The next retreat will then attempt
to follow the rest of the path.  Don't do that.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
2014-02-16 13:19:26 +01:00
40ec33b099 retreat: Reject invalid retreat paths
Undocumented misfeature: retreat and lretreat accept anything as
retreat path.  The paths' actual consumers retreat_ship1() and
retread_land1() silently ignore invalid direction characters.

The retreat paths are in xdump, and invalid ones could conceivably
confuse smart clients.

Change the commands to reject invalid paths, and the consumers to oops
on invalid direction characters.

Note that invalid paths get rejected even when they're not actually
used because the conditions argument contains a "c" for "cancel".
Requiring the user give a new path so he can cancel the old one is
comically bad design.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
2014-02-16 13:19:26 +01:00
b3453efdfc retreat: Don't charge mobility for retreating in direction 'h'
Obscure feature: 'h' in a retreat path stops the current retreat.  The
code treats that as entering the current sector again, thus charges
mobility for staying put.  It also reports "could not retreat to" for
a ship or land unit that can retreat out of, but could not retreat
into its current sector, e.g. a ship in an unfriendly harbor.

Fix by cleaning up the tortuous control flow.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
2014-02-16 13:19:26 +01:00
d1c3529009 retreat: Don't retreat the current player's ships or land units
The retreat code happily retreats anything, without considering who
owns it.  It reports retreat to the owner by bulletin, even when the
owner is the current player.

Commands shouldn't report to the current player by bulletin, they
should print directly.  Fixable.  However, your ships and land units
retreating from your own actions makes little sense.  Suppress it.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
2014-02-16 13:19:26 +01:00
b860123590 retreat: Retreat groups in a more sensible order
A group retreat is executed in increasing UID order.  The resulting
bulletin can be confusing.

Instead, retreat the ship that had its retreat conditions satisfied
first, and only then its group, if any.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
2014-02-16 13:19:25 +01:00
e7949e20f3 retreat: Clear mission only when ship or land unit moves
The mission gets cleared whenever a retreat is triggered, even for
ships and land units that are unable to retreat.

Clear it only when the ship or land unit actually retreats.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
2014-02-16 13:19:25 +01:00
2cc0664e3e retreat: Fix stack smash in land unit group retreat
retreat_land() reads ships instead of land units, overrunning local
variable land.  On lucky systems such as mine, this clobbers ni, and
triggers an oops.  On unlucky systems, it crashes.  On really unlucky
systems, it corrupts the land units file.

Broken since land unit retreat was added in Chainsaw 3.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
2014-02-16 13:19:25 +01:00
58cd269bed tests/retreat: New; exercising retreat
Does not cover land unit retreat after a failed morale check.

The test exposes bugs.  They're marked "BUG:" in the test input.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
2014-02-16 13:19:25 +01:00