patch: fix fuzzing of hunks without previous lines (issue3264) stable
authorPatrick Mezard <patrick@mezard.eu>
Mon, 13 Feb 2012 16:47:31 +0100
branchstable
changeset 16123 b0c7525f826d
parent 16122 9ef3a4a2c6c0
child 16124 0e0060bf2f44
patch: fix fuzzing of hunks without previous lines (issue3264) When applying hunks such as: @@ -2,1 +2,2 @@ context +change fuzzing would empty the "old" block and make patchfile.apply() traceback. Instead, we apply the new block at specified location without testing. The "bottom hunk" test was removed as patch(1) has no problem applying hunk with no context in the middle of a file.
mercurial/patch.py
tests/test-import.t
--- a/mercurial/patch.py	Mon Feb 13 13:51:38 2012 +0100
+++ b/mercurial/patch.py	Mon Feb 13 16:47:31 2012 +0100
@@ -748,20 +748,21 @@
         self.hash = {}
         for x, s in enumerate(self.lines):
             self.hash.setdefault(s, []).append(x)
-        if h.hunk[-1][0] != ' ':
-            # if the hunk tried to put something at the bottom of the file
-            # override the start line and use eof here
-            search_start = len(self.lines)
-        else:
-            search_start = orig_start + self.skew
 
         for fuzzlen in xrange(3):
             for toponly in [True, False]:
                 old, oldstart, new, newstart = h.fuzzit(fuzzlen, toponly)
+                oldstart = oldstart + self.offset + self.skew
+                oldstart = min(oldstart, len(self.lines))
+                if old:
+                    cand = self.findlines(old[0][1:], oldstart)
+                else:
+                    # Only adding lines with no or fuzzed context, just
+                    # take the skew in account
+                    cand = [oldstart]
 
-                cand = self.findlines(old[0][1:], search_start)
                 for l in cand:
-                    if diffhelpers.testhunk(old, self.lines, l) == 0:
+                    if not old or diffhelpers.testhunk(old, self.lines, l) == 0:
                         self.lines[l : l + len(old)] = new
                         self.offset += len(new) - len(old)
                         self.skew = l - orig_start
--- a/tests/test-import.t	Mon Feb 13 13:51:38 2012 +0100
+++ b/tests/test-import.t	Mon Feb 13 16:47:31 2012 +0100
@@ -996,3 +996,79 @@
   c2
   c3
   c4
+
+Test corner case involving fuzz and skew
+
+  $ hg init morecornercases
+  $ cd morecornercases
+
+  $ cat > 01-no-context-beginning-of-file.diff <<EOF
+  > diff --git a/a b/a
+  > --- a/a
+  > +++ b/a
+  > @@ -1,0 +1,1 @@
+  > +line
+  > EOF
+
+  $ cat > 02-no-context-middle-of-file.diff <<EOF
+  > diff --git a/a b/a
+  > --- a/a
+  > +++ b/a
+  > @@ -1,1 +1,1 @@
+  > -2
+  > +add some skew
+  > @@ -2,0 +2,1 @@
+  > +line
+  > EOF
+
+  $ cat > 03-no-context-end-of-file.diff <<EOF
+  > diff --git a/a b/a
+  > --- a/a
+  > +++ b/a
+  > @@ -10,0 +10,1 @@
+  > +line
+  > EOF
+
+  $ cat > a <<EOF
+  > 1
+  > 2
+  > 3
+  > 4
+  > EOF
+  $ hg ci -Am adda a
+  $ for p in *.diff; do
+  >   hg import -v --no-commit $p
+  >   cat a
+  >   hg revert -aqC a
+  >   # patch -p1 < $p
+  >   # cat a
+  >   # hg revert -aC a
+  > done
+  applying 01-no-context-beginning-of-file.diff
+  patching file a
+  applied to working directory
+  1
+  line
+  2
+  3
+  4
+  applying 02-no-context-middle-of-file.diff
+  patching file a
+  Hunk #1 succeeded at 2 (offset 1 lines).
+  Hunk #2 succeeded at 4 (offset 1 lines).
+  applied to working directory
+  1
+  add some skew
+  3
+  line
+  4
+  applying 03-no-context-end-of-file.diff
+  patching file a
+  Hunk #1 succeeded at 5 (offset -6 lines).
+  applied to working directory
+  1
+  2
+  3
+  4
+  line
+