CPack/Deb: Support SOURCE_DATE_EPOCH when packaging files

1 files changed, 26 insertions, 2 deletions

diff --git a/Source/cmArchiveWrite.cxx b/Source/cmArchiveWrite.cxx
index 1dd7734..6031781 100644
--- a/Source/cmArchiveWrite.cxx
+++ b/Source/cmArchiveWrite.cxx
@@ -10,6 +10,7 @@
 #include "cmsys/Encoding.hxx"
 #include "cmsys/FStream.hxx"
 #include <iostream>
+#include <sstream>
 #include <string.h>
 #include <time.h>
 
@@ -94,13 +95,25 @@ cmArchiveWrite::cmArchiveWrite(std::ostream& os, Compress c,
         return;
       }
       break;
-    case CompressGZip:
+    case CompressGZip: {
       if (archive_write_add_filter_gzip(this->Archive) != ARCHIVE_OK) {
         this->Error = "archive_write_add_filter_gzip: ";
         this->Error += cm_archive_error_string(this->Archive);
         return;
       }
-      break;
+      std::string source_date_epoch;
+      cmSystemTools::GetEnv("SOURCE_DATE_EPOCH", source_date_epoch);
+      if (!source_date_epoch.empty()) {
+        // We're not able to specify an arbitrary timestamp for gzip.
+        // The next best thing is to omit the timestamp entirely.
+        if (archive_write_set_filter_option(this->Archive, "gzip", "timestamp",
+                                            nullptr) != ARCHIVE_OK) {
+          this->Error = "archive_write_set_filter_option: ";
+          this->Error += cm_archive_error_string(this->Archive);
+          return;
+        }
+      }
+    } break;
     case CompressBZip2:
       if (archive_write_add_filter_bzip2(this->Archive) != ARCHIVE_OK) {
         this->Error = "archive_write_add_filter_bzip2: ";
@@ -243,6 +256,17 @@ bool cmArchiveWrite::AddFile(const char* file, size_t skip, const char* prefix)
       return false;
     }
     archive_entry_set_mtime(e, t, 0);
+  } else {
+    std::string source_date_epoch;
+    cmSystemTools::GetEnv("SOURCE_DATE_EPOCH", source_date_epoch);
+    if (!source_date_epoch.empty()) {
+      std::istringstream iss(source_date_epoch);
+      time_t epochTime;
+      iss >> epochTime;
+      if (iss.eof() && !iss.fail()) {
+        archive_entry_set_mtime(e, epochTime, 0);
+      }
+    }
   }
 
   // manages the uid/guid of the entry (if any)