Ensure that when the source of a backup is a database that is zero bytes

in size, the final destination database consists of at least one page.
Truncating it to zero bytes is equivalent to zeroing the schema cookie
and change counter, which can cause problems for existing clients.

FossilOrigin-Name: ca86138bda26c5ac5a7e67351acbd19fbd39b0ae

diff --cc manifest
index ca0c8d1cc8c79e9fd5059d45d43aa89a0b60dfbf,efaedf03661bf30df9bc533e23af0408a37322c9..1779f31e8b91f6433ce09efd8026876cf8ba2696
--- 1/manifest
--- 2/manifest
+++ b/manifest
@@@ -1,5 -1,5 +1,5 @@@
- C Allow\sthe\sshowdb\stool\sto\sbe\scompiled\swith\sMSVC.
- D 2012-10-13T09:31:20.156
 -C Mark\san\salways-true\sconditional\sas\ssuch.
 -D 2012-10-13T20:55:12.166
++C Ensure\sthat\swhen\sthe\ssource\sof\sa\sbackup\sis\sa\sdatabase\sthat\sis\szero\sbytes\s\nin\ssize,\sthe\sfinal\sdestination\sdatabase\sconsists\sof\sat\sleast\sone\spage.\s\nTruncating\sit\sto\szero\sbytes\sis\sequivalent\sto\szeroing\sthe\sschema\scookie\s\nand\schange\scounter,\swhich\scan\scause\sproblems\sfor\sexisting\sclients.
++D 2012-10-13T23:16:00.555
  F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
  F Makefile.in 5f4f26109f9d80829122e0e09f9cda008fa065fb
  F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@@ -1019,7 -1020,7 +1020,7 @@@ F tool/vdbe-compress.tcl f12c884766bd14
  F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
  F tool/warnings.sh fbc018d67fd7395f440c28f33ef0f94420226381
  F tool/win/sqlite.vsix 67d8a99aceb56384a81b3f30d6c71743146d2cc9
- P de784399ed1f0e27fc875e32719643d19819c8fb
- R eae4686c36e29e07358a0f64b1678cc7
- U mistachkin
- Z 3d1371a2f131ddfec977348963d5fb7d
 -P 637fb1c1b7642ba3a404dde32e40d4a4ad16fe14
++P dce391fc6302301e9ac53a5e4fc69f3bd7ba13a7 ae025cae2266a91d4226bbdb66f82b9d7714750a
+ R 6411855ed00a2b0cd5f5a66552e9b1b4
+ U drh
 -Z 6ad0f8bd893c2352d9cf2f568adda82f
++Z 1d2efa01eaf44e38b73ed9ee9ed57fac

diff --cc manifest.uuid
index 3bf3a778759a2d753dd1861ebb1f3bb60ffebc36,1030848312eb1cef55442774f2d9cc8bc0eb4016..62b32c975439ba4836b9e52d825818ee64d1da94
--- 1/manifest.uuid
--- 2/manifest.uuid
+++ b/manifest.uuid
@@@ -1,1 -1,1 +1,1 @@@
- dce391fc6302301e9ac53a5e4fc69f3bd7ba13a7
 -ae025cae2266a91d4226bbdb66f82b9d7714750a
++ca86138bda26c5ac5a7e67351acbd19fbd39b0ae