* src/pch.c (intuit_diff_type): Fix regression introduced after patch

2.5.9: when none of the filenames in the old, new, and index headers
exists, patch chose the wrong filename (bug 28367).
(maybe_reverse): Return if the patch looks reversed, not if this
function toggled the reverse flag.
* tests/filename-choice: New test case.
* Makefile.in (TESTS): Add test case.

4 files changed, 59 insertions, 21 deletions

diff --git a/ChangeLog b/ChangeLog
index fd22f6b..724053a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -4,6 +4,14 @@
 
 	* src/pch.c (intuit_diff_type): Add some clarifying comments.
 
+	* src/pch.c (intuit_diff_type): Fix regression introduced after patch
+	2.5.9: when none of the filenames in the old, new, and index headers
+	exists, patch chose the wrong filename (bug 28367).
+	(maybe_reverse): Return if the patch looks reversed, not if this
+	function toggled the reverse flag.
+	* tests/filename-choice: New test case.
+	* Makefile.in (TESTS): Add test case.
+
 2009-11-14  Andreas Gruenbacher  <agruen@suse.de>
 
 	* update-version.sh: Platform compatibility fixes.
diff --git a/Makefile.in b/Makefile.in
index 2c5fb95..04a72ce 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -197,6 +197,7 @@ TESTS = \
 	tests/corrupt-reject-files \
 	tests/create-delete \
 	tests/crlf-handling \
+	tests/filename-choice \
 	tests/global-reject-files \
 	tests/inname \
 	tests/line-numbers \
diff --git a/src/pch.c b/src/pch.c
index a641e12..6982ca3 100644
--- a/src/pch.c
+++ b/src/pch.c
@@ -195,23 +195,22 @@ grow_hunkmax (void)
 }
 
 static bool
-maybe_reverse (char const *name, bool nonexistent, bool empty)
+maybe_reverse (char const *name, bool nonexistent, bool is_empty)
 {
-  bool is_empty = nonexistent || empty;
-  bool r;
-
-  r = (! is_empty) < p_says_nonexistent[reverse ^ is_empty]
-      && ok_to_reverse ("The next patch%s would %s the file %s,\nwhich %s!",
-			reverse ? ", when reversed," : "",
-			(nonexistent ? "delete"
-			 : empty ? "empty out"
-			 : "create"),
-			quotearg (name),
-			(nonexistent ? "does not exist"
-			 : empty ? "is already empty"
-			 : "already exists"));
-  reverse ^= r;
-  return r;
+  bool looks_reversed = (! is_empty) < p_says_nonexistent[reverse ^ is_empty];
+
+  if (looks_reversed)
+    reverse ^=
+      ok_to_reverse ("The next patch%s would %s the file %s,\nwhich %s!",
+		     reverse ? ", when reversed," : "",
+		     (nonexistent ? "delete"
+		      : is_empty ? "empty out"
+		      : "create"),
+		     quotearg (name),
+		     (nonexistent ? "does not exist"
+		      : is_empty ? "is already empty"
+		      : "already exists"));
+  return looks_reversed;
 }
 
 /* True if the remainder of the patch file contains a diff of some sort. */
@@ -681,12 +680,10 @@ intuit_diff_type (bool need_header)
 		    }
 	      }
 
-	    if (i != NONE && st[i].st_size > 0)
-	      i0 = i;
 	    if (i0 != NONE
-		&& ! maybe_reverse (p_name[i0], i == NONE,
-				    i == NONE || st[i].st_size == 0))
-	      i = i0;
+	        && maybe_reverse (p_name[i0], i == NONE,
+				  i == NONE || st[i].st_size == 0))
+		i = i0;
 
 	    if (i == NONE && p_says_nonexistent[reverse])
 	      {
diff --git a/tests/filename-choice b/tests/filename-choice
new file mode 100644
index 0000000..f665afb
--- /dev/null
+++ b/tests/filename-choice
@@ -0,0 +1,32 @@
+# Copyright (C) 2009 Free Software Foundation, Inc.
+#
+# Copying and distribution of this file, with or without modification,
+# in any medium, are permitted without royalty provided the copyright
+# notice and this notice are preserved.
+
+# Don't recognize hunks before a filename has been specified/seen
+
+. $srcdir/test-lib.sh
+
+require_cat
+use_local_patch
+use_tmpdir
+
+# ==============================================================
+
+#export GDB=1
+
+cat > f.diff <<EOF
+--- f
++++ f.new
+@@ -0,0 +1 @@
++content
+EOF
+
+check 'patch -p0 < f.diff' <<EOF
+patching file f
+EOF
+
+check 'cat f' <<EOF
+content
+EOF