Allow no spaces for the last dependency in ParseDepends, too

All other entries in a dependency line get substantial leeway about the
amount of spaces surrounding the entry itself and its individual parts,
but the very last entry was required to have a version constraint be
at least 4 chars long (excluding opening bracket and spaces following
it), so if the version is short and a single-char relation used a space
had to make up for it. This is a bit unfair in comparison to the other
entries who do not have such unreasonable demands, so we reduce our
demand to 3 chars or longer, which is satisfied by "=1)".

If it is a good idea to hate spaces that much remains unanswered by this
commit, but in practice most tools (re)writing the files we parse will
include spaces, so its only in files (or on the satisfy command line)
directly edited by users that we can encounter such a situation, which
is a relatively new development given this line came unchanged from
the introduction of this method in 1998.

LP: #2061834

2 files changed, 34 insertions, 1 deletions

diff --git a/apt-pkg/deb/deblistparser.cc b/apt-pkg/deb/deblistparser.cc
index 46c362952..071189b04 100644
--- a/apt-pkg/deb/deblistparser.cc
+++ b/apt-pkg/deb/deblistparser.cc
@@ -608,7 +608,7 @@ const char *debListParser::ParseDepends(const char *Start, const char *Stop,
    {
       // Skip the '('
       for (I++; I != Stop && isspace_ascii(*I) != 0 ; I++);
-      if (I + 3 >= Stop)
+      if (I + 3 > Stop)
 	 return 0;
       I = ConvertRelation(I,Op);
       
diff --git a/test/libapt/parsedepends_test.cc b/test/libapt/parsedepends_test.cc
index f641c8c1c..454908ef7 100644
--- a/test/libapt/parsedepends_test.cc
+++ b/test/libapt/parsedepends_test.cc
@@ -278,3 +278,36 @@ test:
    if (runner < 8)
       goto test; // this is the prove: tests are really evil ;)
 }
+
+TEST(ParseDependsTest, SpaceHate)
+{
+   auto const *const Depends = "no(=1), some(<<1),some (<<1),some( <<1),some(<< 1),some(<<1 ),some(<<1) ,last (=1)";
+   const char* const End = Depends + strlen(Depends);
+
+   const char* Start = Depends;
+   std::string Package;
+   std::string Version;
+   unsigned int Op = 29;
+
+   Start = debListParser::ParseDepends(Start, End, Package, Version, Op);
+   EXPECT_NE(nullptr, Start);
+   EXPECT_EQ("no", Package);
+   EXPECT_EQ("1", Version);
+   EXPECT_EQ(pkgCache::Dep::Equals, Op);
+
+   for (int i = 0; i < 6; ++i)
+   {
+      SCOPED_TRACE(i);
+      Start = debListParser::ParseDepends(Start, End, Package, Version, Op);
+      EXPECT_NE(nullptr, Start);
+      EXPECT_EQ("some", Package);
+      EXPECT_EQ("1", Version);
+      EXPECT_EQ(pkgCache::Dep::Less, Op);
+   }
+
+   Start = debListParser::ParseDepends(Start, End, Package, Version, Op);
+   EXPECT_EQ(End, Start);
+   EXPECT_EQ("last", Package);
+   EXPECT_EQ("1", Version);
+   EXPECT_EQ(pkgCache::Dep::Equals, Op);
+}