test-convert-hg-startrev: fix test for copy removal on missing parent

The test assumed that 'b' was missing just because the changeset that
introduced 'b' wasn't converted ... but 'b' was also not removed before the
start revision, and the parent was thus not missing at all.

Instead we introduce a file 'f' in rev 0 and remove it in rev 1 so the copy
source really doesn't exist in the repo that is converted from rev 1.

tests/test-convert-hg-startrev.t

@@ -17,22 +17,23 b''
 
   $ echo a > a
   $ echo b > b
-  $ hg ci -d '0 0' -qAm '0: add a b'
+  $ echo f > f
+  $ hg ci -d '0 0' -qAm '0: add a b f'
   $ echo c > c
-  $ hg ci -d '1 0' -qAm '1: add c'
+  $ hg move f d
+  $ hg ci -d '1 0' -qAm '1: add c, move f to d'
   $ hg copy a e
   $ echo b >> b
   $ hg ci -d '2 0' -qAm '2: copy e from a, change b'
   $ hg up -C 0
-  1 files updated, 0 files merged, 2 files removed, 0 files unresolved
+  2 files updated, 0 files merged, 3 files removed, 0 files unresolved
   $ echo a >> a
   $ hg ci -d '3 0' -qAm '3: change a'
   $ hg merge
   merging a and e to e
-  2 files updated, 1 files merged, 0 files removed, 0 files unresolved
+  3 files updated, 1 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
-  $ hg copy b d
-  $ hg ci -d '4 0' -qAm '4: merge 2 and 3, copy d from b'
+  $ hg ci -d '4 0' -qAm '4: merge 2 and 3'
   $ echo a >> a
   $ hg ci -d '5 0' -qAm '5: change a'
   $ cd ..
@@ -44,25 +45,25 b' Convert from null revision'
   scanning source...
   sorting...
   converting...
-  5 0: add a b
-  4 1: add c
+  5 0: add a b f
+  4 1: add c, move f to d
   3 2: copy e from a, change b
   2 3: change a
-  1 4: merge 2 and 3, copy d from b
+  1 4: merge 2 and 3
   0 5: change a
 
   $ glog full
   o  5 "5: change a" files: a
   |
-  o    4 "4: merge 2 and 3, copy d from b" files: d e
+  o    4 "4: merge 2 and 3" files: e f
   |\
   | o  3 "3: change a" files: a
   | |
   o |  2 "2: copy e from a, change b" files: b e
   | |
-  o |  1 "1: add c" files: c
+  o |  1 "1: add c, move f to d" files: c d f
   |/
-  o  0 "0: add a b" files: a b
+  o  0 "0: add a b f" files: a b f
   
   $ rm -Rf full
 
@@ -73,25 +74,25 b' Convert from zero revision'
   scanning source...
   sorting...
   converting...
-  5 0: add a b
-  4 1: add c
+  5 0: add a b f
+  4 1: add c, move f to d
   3 2: copy e from a, change b
   2 3: change a
-  1 4: merge 2 and 3, copy d from b
+  1 4: merge 2 and 3
   0 5: change a
 
   $ glog full
   o  5 "5: change a" files: a
   |
-  o    4 "4: merge 2 and 3, copy d from b" files: d e
+  o    4 "4: merge 2 and 3" files: e f
   |\
   | o  3 "3: change a" files: a
   | |
   o |  2 "2: copy e from a, change b" files: b e
   | |
-  o |  1 "1: add c" files: c
+  o |  1 "1: add c, move f to d" files: c d f
   |/
-  o  0 "0: add a b" files: a b
+  o  0 "0: add a b f" files: a b f
   
 Convert from merge parent
 
@@ -100,19 +101,19 b' Convert from merge parent'
   scanning source...
   sorting...
   converting...
-  3 1: add c
+  3 1: add c, move f to d
   2 2: copy e from a, change b
-  1 4: merge 2 and 3, copy d from b
+  1 4: merge 2 and 3
   0 5: change a
 
   $ glog conv1
   o  3 "5: change a" files: a
   |
-  o  2 "4: merge 2 and 3, copy d from b" files: a d e
+  o  2 "4: merge 2 and 3" files: a e
   |
   o  1 "2: copy e from a, change b" files: b e
   |
-  o  0 "1: add c" files: a b c
+  o  0 "1: add c, move f to d" files: a b c d
   
   $ cd conv1
   $ hg up -q
@@ -120,12 +121,12 b' Convert from merge parent'
 Check copy preservation
 
   $ hg log --follow --copies e
-  changeset:   2:79818a521a40
+  changeset:   2:60633ee11cfa
   user:        test
   date:        Thu Jan 01 00:00:04 1970 +0000
-  summary:     4: merge 2 and 3, copy d from b
+  summary:     4: merge 2 and 3
   
-  changeset:   1:3e6201832cce
+  changeset:   1:d56e8baefff8
   user:        test
   date:        Thu Jan 01 00:00:02 1970 +0000
   summary:     2: copy e from a, change b
@@ -133,10 +134,10 b' Check copy preservation'
 Check copy removal on missing parent
 
   $ hg log --follow --copies d
-  changeset:   2:79818a521a40
+  changeset:   0:23c3be426dce
   user:        test
-  date:        Thu Jan 01 00:00:04 1970 +0000
-  summary:     4: merge 2 and 3, copy d from b
+  date:        Thu Jan 01 00:00:01 1970 +0000
+  summary:     1: add c, move f to d
   
   $ hg cat -r tip a b
   a
@@ -154,12 +155,12 b' Convert from merge'
   scanning source...
   sorting...
   converting...
-  1 4: merge 2 and 3, copy d from b
+  1 4: merge 2 and 3
   0 5: change a
   $ glog conv4
   o  1 "5: change a" files: a
   |
-  o  0 "4: merge 2 and 3, copy d from b" files: a b c d e
+  o  0 "4: merge 2 and 3" files: a b c d e
   
   $ cd conv4
   $ hg up -C