mq: correctly make an empty line after description in new patches

There would in some cases be an empty line between headers and the description -
that does not seem right.

There should also be an empty line between description and diff - but that was
missing.

These two mistakes would sometimes make it up for each other so we fix both at
once to just show the improvement.

Instead of writing an extra newline when writing a header line, write an extra
line when it not is written as a part of the description but is necessary
anyway.

hgext/mq.py

@@ -1073,10 +1073,8 b' class queue(object):'
                 if self.plainmode:
                     if user:
                         p.write("From: " + user + "\n")
-                        if not date:
-                            p.write("\n")
                     if date:
-                        p.write("Date: %d %d\n\n" % date)
+                        p.write("Date: %d %d\n" % date)
                 else:
                     p.write("# HG changeset patch\n")
                     p.write("# Parent "
@@ -1084,7 +1082,7 b' class queue(object):'
                     if user:
                         p.write("# User " + user + "\n")
                     if date:
-                        p.write("# Date %s %s\n\n" % date)
+                        p.write("# Date %s %s\n" % date)
 
                 defaultmsg = "[mq]: %s" % patchfn
                 editor = cmdutil.getcommiteditor(editform=editform)
@@ -1117,6 +1115,8 b' class queue(object):'
                     if nctx.description() != defaultmsg.rstrip():
                         msg = nctx.description() + "\n\n"
                         p.write(msg)
+                    elif not self.plainmode or date or user:
+                        p.write('\n')
                     if commitfiles:
                         parent = self.qparents(repo, n)
                         if inclsubs:

tests/test-mq-header-date.t

@@ -243,7 +243,6 b''
   now at: 1.patch
   ==== qnew -d -m
   Date: 6 0
-  
   Three
   
   1: Three - test - 6.00
@@ -251,7 +250,6 b''
   ==== qref
   adding 3
   Date: 6 0
-  
   Three
   
   diff -r ... 3
@@ -263,7 +261,6 b''
   0: [mq]: 1.patch - test - 4.00
   ==== qref -m
   Date: 6 0
-  
   Drei
   
   diff -r ... 3
@@ -275,7 +272,6 b''
   0: [mq]: 1.patch - test - 4.00
   ==== qref -d
   Date: 7 0
-  
   Drei
   
   diff -r ... 3
@@ -287,7 +283,6 b''
   0: [mq]: 1.patch - test - 4.00
   ==== qref -d -m
   Date: 8 0
-  
   Three (again)
   
   diff -r ... 3
@@ -590,7 +585,6 b''
   # HG changeset patch
   # Parent 
   # Date 6 0
-  
   Three
   
   1: Three - test - 6.00
@@ -600,7 +594,6 b''
   # HG changeset patch
   # Parent 
   # Date 6 0
-  
   Three
   
   diff -r ... 3
@@ -614,7 +607,6 b''
   # HG changeset patch
   # Parent 
   # Date 6 0
-  
   Drei
   
   diff -r ... 3
@@ -628,7 +620,6 b''
   # HG changeset patch
   # Parent 
   # Date 7 0
-  
   Drei
   
   diff -r ... 3
@@ -642,7 +633,6 b''
   # HG changeset patch
   # Parent 
   # Date 8 0
-  
   Three (again)
   
   diff -r ... 3

tests/test-mq-header-from.t

@@ -176,7 +176,6 b''
   0: [mq]: 1.patch - mary
   ==== qnew -U -m
   From: test
-  
   Three
   
   2: Three - test
@@ -185,7 +184,6 b''
   ==== qref
   adding 3
   From: test
-  
   Three
   
   diff -r ... 3
@@ -198,7 +196,6 b''
   0: [mq]: 1.patch - mary
   ==== qref -m
   From: test
-  
   Drei
   
   diff -r ... 3
@@ -211,7 +208,6 b''
   0: [mq]: 1.patch - mary
   ==== qref -u
   From: mary
-  
   Drei
   
   diff -r ... 3
@@ -224,7 +220,6 b''
   0: [mq]: 1.patch - mary
   ==== qref -u -m
   From: maria
-  
   Three (again)
   
   diff -r ... 3
@@ -406,6 +401,7 b''
   # HG changeset patch
   # Parent 
   # User test
+  
   0: [mq]: 1.patch - test
   ==== qref
   adding 1
@@ -690,6 +686,7 b''
   # HG changeset patch
   # Parent 
   # User test
+  
   0: [mq]: 1.patch - test
   ==== qref
   adding 1

tests/test-mq-qnew.t

@@ -209,6 +209,7 b' hg headers'
   M d/b
   # HG changeset patch
   # Parent 
+  
   diff --git a/d/b b/d/b
   --- a/d/b
   +++ b/d/b
@@ -219,10 +220,12 b' hg headers'
   # HG changeset patch
   # Parent 
   # User blue
+  
   % qnew -e -u with no username configured
   # HG changeset patch
   # Parent 
   # User chartreuse
+  
   % fail when trying to import a merge
   adding a
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
@@ -337,6 +340,7 b' Test handling default message with the p'
   $ cat ".hg/patches/patch "
   # HG changeset patch
   # Parent 0000000000000000000000000000000000000000
+  
 
   $ cd ..
 

tests/test-mq-qrefresh.t

@@ -508,6 +508,7 b' but only after writing the bad name into'
   $ cat .hg/patches/a
   # HG changeset patch
   # Parent 0000000000000000000000000000000000000000
+  
   diff --git a/a b/a
   new file mode 100644
   $ hg qpush
@@ -522,6 +523,7 b' but only after writing the bad name into'
   $ cat .hg/patches/a
   # HG changeset patch
   # Parent 0000000000000000000000000000000000000000
+  
   diff --git a/a b/a
   new file mode 100644
   $ cd ..