fix: Don't crash when attempting to download non-existent file.

Fixes #21.

Specifically, it fixes the crash that happens because of the ship's
index file no longer existing of the EDCD coriolois data github.

So the Ships database won't be getting updated until a new source is
found to download from.

For now the latest version available before the removal is stored as a
template.

TD will get another update once we have a new site from which to get the
index again.

setup.py

@@ -23,38 +23,38 @@
 
 package = "tradedangerous"
 
-exec(open("tradedangerous/version.py").read()) #pylint: disable=W0122
+exec(open("tradedangerous/version.py").read())  # pylint: disable=W0122
 
-setup(name=package,
-        version=__version__, #pylint: disable=E0602
-        install_requires=["requests"],
-        setup_requires=["pytest-runner"],
-        tests_require=["pytest"],
-        packages=['tradedangerous', 'tradedangerous.commands', 'tradedangerous.mfd', 'tradedangerous.mfd.saitek', 'tradedangerous.misc', 'tradedangerous.plugins'],
-        url="https://github.com/eyeonus/Trade-Dangerous",
-        project_urls={
+setup(name = package,
+        version = __version__,  # pylint: disable=E0602
+        install_requires = ["requests"],
+        setup_requires = ["pytest-runner"],
+        tests_require = ["pytest"],
+        packages = ['tradedangerous', 'tradedangerous.commands', 'tradedangerous.mfd', 'tradedangerous.mfd.saitek', 'tradedangerous.misc', 'tradedangerous.plugins'],
+        url = "https://github.com/eyeonus/Trade-Dangerous",
+        project_urls = {
             "Bug Tracker": "https://github.com/eyeonus/Trade-Dangerous/issues",
             "Documentation": "https://github.com/eyeonus/Trade-Dangerous/wiki",
             "Source Code": "https://github.com/eyeonus/Trade-Dangerous",
         },
-        author="eyeonus",
-        author_email="eyeonus@gmail.com",
-        description="Trade-Dangerous is a set of powerful trading tools for Elite Dangerous, organized around one of the most powerful trade run optimizers available.",
-        long_description=long_description,
-        long_description_content_type="text/markdown",
-        keywords=["trade", "elite", "elite-dangerous"],
-        classifiers=[
+        author = "eyeonus",
+        author_email = "eyeonus@gmail.com",
+        description = "Trade-Dangerous is a set of powerful trading tools for Elite Dangerous, organized around one of the most powerful trade run optimizers available.",
+        long_description = long_description,
+        long_description_content_type = "text/markdown",
+        keywords = ["trade", "elite", "elite-dangerous"],
+        classifiers = [
             "Programming Language :: Python :: 3",
             "License :: OSI Approved :: MIT License",
             "Operating System :: OS Independent",
         ],
-        license="MPL",
-        test_suite="tests",
-        package_data={"tradedangerous": ["templates/TradeDangerous.sql", "templates/Added.csv", "templates/RareItem.csv"]},
-        entry_points={
+        license = "MPL",
+        test_suite = "tests",
+        package_data = {"tradedangerous": ["templates/TradeDangerous.sql", "templates/Added.csv", "templates/RareItem.csv", "templates/DefaultShipIndex.json"]},
+        entry_points = {
             "console_scripts": [
                 "trade=tradedangerous.cli:main"
             ]
         },
-        zip_safe=False
+        zip_safe = False
 )

tradedangerous/plugins/eddblink_plug.py

@@ -21,6 +21,7 @@
 from .. import plugins, cache, csvexport, tradedb, tradeenv, transfers
 from ..misc import progress as pbar
 from ..plugins import PluginException
+from shutil import copyfile
 
 # Constants
 BASE_URL = os.environ.get('TD_SERVER') or "http://elite.tromador.com/files/"
@@ -155,25 +156,36 @@ def downloadFile(self, urlTail, path):
         """
         tdb, tdenv = self.tdb, self.tdenv
 
-        tdenv.DEBUG0("Checking for update to '{}'.", path)
+        tdenv.NOTE("Checking for update to '{}'.", path)
         if urlTail == SHIPS_URL:
             url = SHIPS_URL
         else:
-            if not self.getOption('fallback'):
-                try:
-                    url = BASE_URL + urlTail
-                    response = request.urlopen(url)
-                except:
-                    # If Tromador's server fails for whatever reason,
-                    # fallback to download direct from EDDB.io
-                    self.options["fallback"] = True
-            if self.getOption('fallback'):
-                # EDDB.io doesn't have live listings.
-                if urlTail == LIVE_LISTINGS:
-                    return False
-
-                url = FALLBACK_URL + urlTail
+            url = BASE_URL + urlTail
+        if url == SHIPS_URL or not self.getOption('fallback'):
+            try:
                 response = request.urlopen(url)
+            except Exception as e:
+                # If Tromador's server fails for whatever reason,
+                # fallback to download direct from EDDB.io
+                tdenv.WARN("Problem with download:\nURL: {}\nError: {}", url, str(e))
+                self.options["fallback"] = True
+
+        if self.getOption('fallback'):
+            # EDDB.io doesn't have live listings or the ship index.
+            if urlTail == LIVE_LISTINGS:
+                return False
+
+            if urlTail == SHIPS_URL:
+                tdenv.NOTE("Using Default Ship Index.")
+                copyfile(self.tdenv.templateDir / Path("DefaultShipIndex.json"), self.dataPath / path)
+                return True
+
+            url = FALLBACK_URL + urlTail
+            try:
+                response = request.urlopen(url)
+            except Exception as e:
+                tdenv.WARN("Problem with download (fallback enabled):\nURL: {}\nError: {}", url, str(e))
+                return False
 
         dumpModded = 0
         # The coriolis file is from github, so it doesn't have a "Last-Modified" metadata.