tests: restore some !MINGW prereqs

Even when built with the import-url feature, the "file://" schemed urls
used in the tests don't work on Windows due to the slashy,
drive-letter-less path not being portable to Windows.

Author: jpgrayson

t/t1800-import.sh

@@ -163,7 +163,7 @@ test_expect_success 'Apply a patch and edit message' '
     stg delete ..
 '
 
-test_expect_success STG_IMPORT_URL 'Apply a patch from a URL' '
+test_expect_success !MINGW,STG_IMPORT_URL 'Apply a patch from a URL' '
     stg import -u "file://$TEST_DIRECTORY/t1800/git-diff" &&
     [ $(git cat-file -p $(stg id) \
       | grep -c "tree e96b1fba2160890ff600b675d7140d46b022b155") = 1 ] &&
@@ -255,21 +255,23 @@ test_expect_success 'Apply a series from a tarball' '
     stg delete ..
 '
 
-test_expect_success STG_IMPORT_URL 'Apply a series from a tarball url' '
+test_expect_success !MINGW,STG_IMPORT_URL 'Apply a series from a tarball url' '
     stg import --url --series "file://$(pwd)/jabberwocky.tar.bz2" &&
     [ $(git cat-file -p $(stg id) \
-        | grep -c "tree 2c33937252a21f1550c0bf21f1de534b68f69635") = 1 ]
+        | grep -c "tree 2c33937252a21f1550c0bf21f1de534b68f69635") = 1 ] &&
+    stg show | grep -e "Author: Clark Williams <[email protected]>" &&
+    stg delete ..
 '
 
-test_expect_success !STG_IMPORT_URL 'Apply a series from a abs tarball path' '
+test_expect_success 'Apply a series from a abs tarball path' '
     stg import --series "$(pwd)/jabberwocky.tar.bz2" &&
     [ $(git cat-file -p $(stg id) \
-        | grep -c "tree 2c33937252a21f1550c0bf21f1de534b68f69635") = 1 ]
+        | grep -c "tree 2c33937252a21f1550c0bf21f1de534b68f69635") = 1 ] &&
+    stg show | grep -e "Author: Clark Williams <[email protected]>" &&
+    stg delete --top --spill
 '
 
 test_expect_success 'Import with author options' '
-    stg show | grep -e "Author: Clark Williams <[email protected]>" &&
-    stg delete --top --spill &&
     stg diff >some.patch &&
     git reset jabberwocky.txt &&
     git checkout jabberwocky.txt &&

t/t1801-import-email.sh

@@ -21,7 +21,7 @@ test_expect_success 'Apply a patch from an 8bit-encoded e-mail' '
     stg delete ..
 '
 
-test_expect_success STG_IMPORT_URL 'Apply a patch from an 8bit-encoded e-mail url' '
+test_expect_success !MINGW,STG_IMPORT_URL 'Apply a patch from an 8bit-encoded e-mail url' '
     stg import -u -m "file://$TEST_DIRECTORY"/t1801/email-8bit &&
     [ $(git cat-file -p $(stg id) \
         | grep -c "tree 030be42660323ff2a1958f9ee79589a4f3fbee2f") = 1 ] &&
@@ -118,7 +118,7 @@ test_expect_success 'Apply several patches from an mbox file' '
     stg delete ..
 '
 
-test_expect_success STG_IMPORT_URL 'Apply several patches from an mbox url' '
+test_expect_success !MINGW,STG_IMPORT_URL 'Apply several patches from an mbox url' '
     test_config stgit.import.message-id "yes" &&
     stg import -u -M "file://$TEST_DIRECTORY"/t1801/email-mbox &&
     [ $(git cat-file -p $(stg id change-1) \