fix: a resumed download is not counted as speed

The live line divided every byte by the run's time, a partial copy left by an earlier run included, and showed a 3 GB resume as 2.5 GB/s with nothing left.

install.ps1

@@ -8,7 +8,7 @@ param(
 
 $ErrorActionPreference = "Stop"
 $defaultInstallUrl = "https://raw.githubusercontent.com/Abdess/retrobios/main/install.py"
-$defaultInstallSha256 = "2db3ce4cf58905d34d45633e7d955ba106b343f8348c8bd81ece5731560d331c"
+$defaultInstallSha256 = "bc7e519f5bc6dbbc062a0ac29558dbe6862299e6d511b97c048f52ce2db5fba3"
 $maximumInstallerBytes = 2MB
 $installerExit = 0
 $installer = if ($PSScriptRoot) { Join-Path $PSScriptRoot "install.py" } else { $null }

install.py

@@ -347,7 +347,9 @@ class Progress:
     def _draw(self) -> None:
         share = min(self.bytes / self.total_bytes, 1.0)
         elapsed = self.elapsed()
-        speed = self.bytes / elapsed if elapsed > 0 else 0
+        # A resumed partial copy was on disk before the run started: counted
+        # in the share, never in the speed.
+        speed = self.transferred() / elapsed if elapsed > 0 else 0
         left = (self.total_bytes - self.bytes) / speed if speed > 0 else 0
         parts = [
             f"{share * 100:5.1f}%",

install.sh

@@ -18,7 +18,7 @@ esac
 TEMP_INSTALLER=""
 TEMP_DIRECTORY=""
 DEFAULT_INSTALL_URL="https://raw.githubusercontent.com/Abdess/retrobios/main/install.py"
-DEFAULT_INSTALL_SHA256="2db3ce4cf58905d34d45633e7d955ba106b343f8348c8bd81ece5731560d331c"
+DEFAULT_INSTALL_SHA256="bc7e519f5bc6dbbc062a0ac29558dbe6862299e6d511b97c048f52ce2db5fba3"
 MAX_INSTALLER_BYTES=2097152
 
 cleanup() {

tests/test_install.py

@@ -2782,6 +2782,32 @@ class TheProgressLineFitsTheTerminal(unittest.TestCase):
 
 
 
+class AResumedCopyIsNotSpeed(unittest.TestCase):
+    """The live line divided every byte by the run's time, the 3 GB a
+    resumed partial copy already held included: 2.5 GB/s and 0:00 left on a
+    1 MB/s link."""
+
+    def test_speed_counts_only_what_this_run_fetched(self):
+        import os as _os
+
+        out = io.StringIO()
+        term = install.Terminal(out)
+        term.live = True
+        progress = install.Progress(1, 4_000_000_000, term)
+        progress.start -= 10
+        progress.bytes = 3_000_000_000 + 10_000_000
+        progress.resumed = 3_000_000_000
+        with unittest.mock.patch.object(
+            install.shutil, "get_terminal_size",
+            return_value=_os.terminal_size((120, 24)),
+        ):
+            progress._draw()
+        line = out.getvalue()
+        self.assertIn(f"{install.format_size(1_000_000)}/s", line)
+        self.assertNotIn("0:00 left", line)
+
+
+
 class ThePagesQuoteTheBootstrapsOwnWords(unittest.TestCase):
     """The installer page and the FAQ quoted "install.py SHA-256 mismatch",
     a message the bootstraps no longer print."""