From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Tue, 10 Jan 2017 14:22:55 +0000 (+0000)
Subject: dgit: dsc download handling: save as ,fetch if need be
X-Git-Tag: archive/debian/3.1~3
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=dgit.git;a=commitdiff_plain;h=f233a3d733538a94a042b9f3c3dc0339c8473ab8

dgit: dsc download handling: save as ,fetch if need be

* Pass \$refetched to complete_file_from_dsc, so that we refetch files
  whose hashes are wrong.

* When saving files we refetched, save them as F,fetch if saving them
  as F gives EEXIST.  So we can save refetched files.

* When looking for files to reuse, look for F,fetch first.

We do this only here in generate_commits_from_dsc, not in
ensure_we_have_orig.  This is because, in practice, this all won't be
very effective for origs which need to be referred to by various
.dscs.

The main use case is when the user did a build without changing the
version number.  This would otherwise break fetch: Closes:#850824.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---

diff --git a/debian/changelog b/debian/changelog
index 52e54ce8..607b2cd5 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -5,6 +5,9 @@ dgit (3.1~) unstable; urgency=medium
   * dgit: Do not nedlessly re-fetch the rewrite map.
   * dgit: After downloading .debian.* files, save them in `..', too
     (ie do this not just for .origs).
+  * dgit: When fetching, refetch files with hash mismatches (and save them
+    as `...,fetch'), so we can distinguish them from any built locally.
+    Closes:#850824.
 
   Test suite:
   * Add test for import-dsc with default distro.  (Detects #850781.)
diff --git a/dgit b/dgit
index 0cd122ef..a51c8782 100755
--- a/dgit
+++ b/dgit
@@ -2072,21 +2072,43 @@ sub generate_commits_from_dsc () {
 	die "$f ?" if $f =~ m#/|^\.|\.dsc$|\.tmp$#;
 	my $upper_f = "../../../../$f";
 
-	printdebug "considering linking $f: ";
-
-	link_ltarget $upper_f, $f
-	    or ((printdebug "($!) "), 0)
-	    or $!==&ENOENT
-	    or die "$f $!";
-
-	printdebug "linked.\n";
+	printdebug "considering reusing $f: ";
+
+	if (link_ltarget "$upper_f,fetch", $f) {
+	    printdebug "linked (using ...,fetch).\n";
+	} elsif ((printdebug "($!) "),
+		 $! != ENOENT) {
+	    fail "accessing ../$f,fetch: $!";
+	} elsif (link_ltarget $upper_f, $f) {
+	    printdebug "linked.\n";
+	} elsif ((printdebug "($!) "),
+		 $! != ENOENT) {
+	    fail "accessing ../$f: $!";
+	} else {
+	    printdebug "absent.\n";
+	}
 
-	complete_file_from_dsc('.', $fi)
+	my $refetched;
+	complete_file_from_dsc('.', $fi, \$refetched)
 	    or next;
 
-	link $f, $upper_f
-	    or $!==&EEXIST
-	    or die "$f $!";
+	printdebug "considering saving $f: ";
+
+	if (link $f, $upper_f) {
+	    printdebug "linked.\n";
+	} elsif ((printdebug "($!) "),
+		 $! != EEXIST) {
+	    fail "saving ../$f: $!";
+	} elsif (!$refetched) {
+	    printdebug "no need.\n";
+	} elsif (link $f, "$upper_f,fetch") {
+	    printdebug "linked (using ...,fetch).\n";
+	} elsif ((printdebug "($!) "),
+		 $! != EEXIST) {
+	    fail "saving ../$f,fetch: $!";
+	} else {
+	    printdebug "cannot.\n";
+	}
     }
 
     # We unpack and record the orig tarballs first, so that we only