Merge pull request #15 from logos-co/fix/preserve-file-permissions

fix: Preserve file permissions when writing tar.

Author: iurimatias

.gitignore

@@ -2,3 +2,4 @@ build/
 .DS_Store
 Testing/
 result
+.idea/

src/core/package.cpp

@@ -129,7 +129,7 @@ Package::Result Package::save(const std::filesystem::path& lgxPath) const {
                 addedDirs.insert(dirPath);
             }
         } else {
-            writer.addFile(entry.path, entry.data);
+            writer.addEntry(entry);
         }
     }
 
@@ -452,12 +452,24 @@ Package::Result Package::addFilesystemEntries(
         entry.path = normalizedBase;
         entry.data = std::move(data);
         entry.isDirectory = false;
+        
+        auto status = fs::status(fsPath, ec);
+        if (!ec) {
+            entry.mode = static_cast<uint32_t>(status.permissions() & fs::perms::mask);
+        }
+        
         entries_.push_back(std::move(entry));
     } else if (fs::is_directory(fsPath, ec)) {
         // Directory - add entry for the directory itself
         TarEntry dirEntry;
         dirEntry.path = normalizedBase;
         dirEntry.isDirectory = true;
+        
+        auto status = fs::status(fsPath, ec);
+        if (!ec) {
+            dirEntry.mode = static_cast<uint32_t>(status.permissions() & fs::perms::mask);
+        }
+        
         entries_.push_back(dirEntry);
 
         // Recursively add contents
@@ -481,6 +493,12 @@ Package::Result Package::addFilesystemEntries(
                 TarEntry entry;
                 entry.path = *normalizedPathOpt;
                 entry.isDirectory = true;
+                
+                auto status = fs::status(item.path(), ec);
+                if (!ec) {
+                    entry.mode = static_cast<uint32_t>(status.permissions() & fs::perms::mask);
+                }
+                
                 entries_.push_back(std::move(entry));
             } else if (fs::is_regular_file(item.path(), ec)) {
                 std::ifstream file(item.path(), std::ios::binary);
@@ -497,6 +515,12 @@ Package::Result Package::addFilesystemEntries(
                 entry.path = *normalizedPathOpt;
                 entry.data = std::move(data);
                 entry.isDirectory = false;
+                
+                auto status = fs::status(item.path(), ec);
+                if (!ec) {
+                    entry.mode = static_cast<uint32_t>(status.permissions() & fs::perms::mask);
+                }
+                
                 entries_.push_back(std::move(entry));
             } else {
                 // Skip symlinks, special files, etc.
@@ -577,6 +601,14 @@ Package::Result Package::extractVariant(
             if (!file) {
                 return Result::fail("Failed to write file: " + fullPath.string());
             }
+            file.close();
+
+            if (entry.mode != 0) {
+                fs::permissions(fullPath, static_cast<fs::perms>(entry.mode & 0777), ec);
+                if (ec) {
+                    return Result::fail("Failed to set permissions on: " + fullPath.string() + " - " + ec.message());
+                }
+            }
         }
     }
 

src/core/tar_reader.cpp

@@ -158,9 +158,7 @@ TarReader::ReadResult TarReader::read(const std::vector<uint8_t>& tarData) {
         zeroBlockCount = 0;
         const auto& info = *infoOpt;
 
-        TarEntry entry;
-        entry.path = info.path;
-        entry.isDirectory = info.isDirectory;
+        TarEntry entry(info.path, info.isDirectory, info.mode);
 
         // Move past header
         offset += BLOCK_SIZE;
@@ -324,10 +322,8 @@ bool TarReader::iterate(
         zeroBlockCount = 0;
         const auto& info = *infoOpt;
 
-        TarEntry entry;
-        entry.path = info.path;
-        entry.isDirectory = info.isDirectory;
-        
+        TarEntry entry(info.path, info.isDirectory, info.mode);
+
         // Move past header
         offset += BLOCK_SIZE;
 

src/core/tar_writer.cpp

@@ -128,9 +128,15 @@ std::vector<uint8_t> DeterministicTarWriter::createHeader(const TarEntry& entry)
 
     // Name (0-99)
     std::memcpy(header.data(), name.c_str(), std::min(name.length(), NAME_SIZE));
-    
+
     // Mode (100-107)
-    writeOctal(header.data() + 100, 8, entry.isDirectory ? DIR_MODE : FILE_MODE);
+    uint32_t mode = entry.mode & 0777;
+    if (entry.isDirectory) {
+        mode = DIR_MODE;
+    } else if (mode == 0) {
+        mode = FILE_MODE;
+    }
+    writeOctal(header.data() + 100, 8, mode);
 
     // UID (108-115)
     writeOctal(header.data() + 108, 8, UID);

src/core/tar_writer.h

@@ -16,12 +16,15 @@ struct TarEntry {
     std::string path;           // NFC-normalized archive path
     std::vector<uint8_t> data;  // File contents (empty for directories)
     bool isDirectory;
+    uint32_t mode;              // File mode (permissions)
 
-    TarEntry() : isDirectory(false) {}
-    TarEntry(const std::string& p, bool isDir = false) 
-        : path(p), isDirectory(isDir) {}
-    TarEntry(const std::string& p, const std::vector<uint8_t>& d)
-        : path(p), data(d), isDirectory(false) {}
+    TarEntry() : isDirectory(false), mode(0) {}
+    TarEntry(const std::string& p, bool isDir = false, uint32_t m = 0) 
+        : path(p), isDirectory(isDir), mode(m) {}
+    TarEntry(const std::string& p, const std::vector<uint8_t>& d, uint32_t m = 0)
+        : path(p), data(d), isDirectory(false), mode(m) {}
+    TarEntry(const std::string& p, const std::string& d, uint32_t m = 0)
+        : path(p), data(d.begin(), d.end()), isDirectory(false), mode(m) {}
 };
 
 /**
@@ -30,7 +33,7 @@ struct TarEntry {
  * Determinism is achieved by:
  * - Lexicographic sorting of entries by NFC-normalized path bytes
  * - Fixed metadata: uid=0, gid=0, uname="", gname="", mtime=0
- * - Fixed modes: dirs=0755, files=0644
+ * - Modes: dirs=0755, files preserve their mode or 0644 if not set
  * - USTAR format for consistency
  */
 class DeterministicTarWriter {

tests/test_tar_writer.cpp

@@ -150,6 +150,30 @@ TEST(TarWriterTest, FixedMetadata) {
     }
 }
 
+TEST(TarWriterTest, CustomMode) {
+    DeterministicTarWriter writer;
+    
+    // Add file with custom mode
+    TarEntry entry1("script.sh", std::string("echo hello"), 0700);
+    writer.addEntry(entry1);
+    
+    // Add directory with custom mode
+    TarEntry entry2("tools", true, 0777);
+    writer.addEntry(entry2);
+    
+    auto tarData = writer.finalize();
+    auto result = TarReader::read(tarData);
+    ASSERT_TRUE(result.success);
+    ASSERT_EQ(result.entries.size(), 2);
+    
+    // Entries are sorted lexicographically: script.sh, tools
+    EXPECT_EQ(result.entries[0].path, "script.sh");
+    EXPECT_EQ(result.entries[0].mode, 0700);
+    
+    EXPECT_EQ(result.entries[1].path, "tools/");
+    EXPECT_EQ(result.entries[1].mode, 0755); // Directories now always DIR_MODE (0755)
+}
+
 // =============================================================================
 // Roundtrip Tests
 // =============================================================================