Fix null/empty filename string when downloading package file (#293)

microsoft · Aug 4, 2022 · 3ea6614 · 3ea6614
1 parent 99cc214
commit 3ea6614
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Showing 2 changed files with 17 additions and 5 deletions.
diff --git a/src/WingetCreateCore/Common/Extensions.cs b/src/WingetCreateCore/Common/Extensions.cs
@@ -93,6 +93,16 @@ public static string ToEnumAttributeValue(this Enum enumVal)
             var attributes = memInfo[0].GetCustomAttributes(typeof(EnumMemberAttribute), false);
             EnumMemberAttribute attributeValue = (attributes.Length > 0) ? (EnumMemberAttribute)attributes[0] : null;
             return attributeValue?.Value ?? enumVal.ToString();
+        }
+
+        /// <summary>
+        /// Returns null if the target string is empty.
+        /// </summary>
+        /// <param name="s">Target string value.</param>
+        /// <returns>Null if the string is empty; otherwise the original string value.</returns>
+        public static string NullIfEmpty(this string s)
+        {
+            return string.IsNullOrEmpty(s) ? null : s;
         }
 
         /// <summary>

diff --git a/src/WingetCreateCore/Common/PackageParser.cs b/src/WingetCreateCore/Common/PackageParser.cs
@@ -135,15 +135,17 @@ public static async Task<string> DownloadFileAsync(string url, long? maxDownload
             }
 
             string urlFile = Path.GetFileName(url.Split('?').Last());
-            string contentDispositionFile = response.Content.Headers.ContentDisposition?.FileName?.Trim('"');
+            string contentDispositionFile = response.Content.Headers.ContentDisposition?.FileName?.Trim('"');
+            string requestUrlFileName = Path.GetFileName(response.RequestMessage?.RequestUri?.ToString());
 
             if (!Directory.Exists(InstallerDownloadPath))
             {
                 Directory.CreateDirectory(InstallerDownloadPath);
-            }
-
-            string targetFile = GetNumericFilename(Path.Combine(InstallerDownloadPath, contentDispositionFile ?? urlFile));
-
+            }
+
+            // If no relevant filename can be obtained for the installer download, use a temporary filename as last option.
+            string targetFileName = contentDispositionFile.NullIfEmpty() ?? urlFile.NullIfEmpty() ?? requestUrlFileName.NullIfEmpty() ?? Path.GetTempFileName();
+            string targetFile = GetNumericFilename(Path.Combine(InstallerDownloadPath, targetFileName));
             using var targetFileStream = File.OpenWrite(targetFile);
             var contentStream = await response.Content.ReadAsStreamAsync();