patch, 5 partsgit-merge-fredrik updates

diff --git a/git-merge-fredrik.py b/git-merge-fredrik.py
--- a/git-merge-fredrik.py
+++ b/git-merge-fredrik.py
@@ -60,7 +60,7 @@ def merge(h1, h2, branch1Name, branch2Na
                                  branch1Name, branch2Name,
                                  cleanCache, updateWd)
 
-    if clean or alwaysWriteTree:
+    if clean or cleanCache:
         res = Commit(None, [h1, h2], tree=shaRes)
         graph.addNode(res)
     else:

diff --git a/git-merge-fredrik.py b/git-merge-fredrik.py
--- a/git-merge-fredrik.py
+++ b/git-merge-fredrik.py
@@ -1,6 +1,6 @@
 #!/usr/bin/python
 
-import sys, math, random, os, re, signal, tempfile, stat, errno
+import sys, math, random, os, re, signal, tempfile, stat, errno, traceback
 from heapq import heappush, heappop
 from sets import Set
 
@@ -409,15 +409,20 @@ for nextArg in xrange(1, len(sys.argv)):
         break
 
 print 'Merging', h1, 'with', h2
-h1 = runProgram(['git-rev-parse', '--verify', h1 + '^0']).rstrip()
-h2 = runProgram(['git-rev-parse', '--verify', h2 + '^0']).rstrip()
 
-graph = buildGraph([h1, h2])
-
-[res, clean] = merge(graph.shaMap[h1], graph.shaMap[h2],
-                     firstBranch, secondBranch, graph)
-
-print ''
+try:
+    h1 = runProgram(['git-rev-parse', '--verify', h1 + '^0']).rstrip()
+    h2 = runProgram(['git-rev-parse', '--verify', h2 + '^0']).rstrip()
+
+    graph = buildGraph([h1, h2])
+
+    [res, clean] = merge(graph.shaMap[h1], graph.shaMap[h2],
+                         firstBranch, secondBranch, graph)
+
+    print ''
+except:
+    traceback.print_exc(None, sys.stderr)
+    sys.exit(2)
 
 if clean:
     sys.exit(0)

git-merge-fredrik.py, gitMergeCommon.py

diff --git a/git-merge-fredrik.py b/git-merge-fredrik.py
--- a/git-merge-fredrik.py
+++ b/git-merge-fredrik.py
@@ -120,9 +120,8 @@ def unmergedCacheEntries():
             e.stages[stage].mode = mode
             e.stages[stage].sha1 = sha1
         else:
-            print 'Error: Merge program failed: Unexpected output from', \
-                  'git-ls-files:', l
-            sys.exit(2)
+            die('Error: Merge program failed: Unexpected output from', \
+                'git-ls-files:', l)
     return res
 
 def mergeTrees(head, merge, common, branch1Name, branch2Name,
@@ -381,15 +380,12 @@ def processEntry(entry, branch1Name, bra
         os.unlink(src1)
         os.unlink(src2)
     else:
-        print 'ERROR: Fatal merge failure.'
-        print "ERROR: Shouldn't happen"
-        sys.exit(2)
+        die("ERROR: Fatal merge failure, shouldn't happen.")
 
     return cleanMerge
 
 def usage():
-    print 'Usage:', sys.argv[0], ' <base>... -- <head> <remote>..'
-    sys.exit(2)
+    die('Usage:', sys.argv[0], ' <base>... -- <head> <remote>..')
 
 # main entry point as merge strategy module
 # The first parameters up to -- are merge bases, and the rest are heads.
@@ -399,8 +395,7 @@ def usage():
 for nextArg in xrange(1, len(sys.argv)):
     if sys.argv[nextArg] == '--':
         if len(sys.argv) != nextArg + 3:
-            print 'Not handling anything other than two heads merge.'
-            sys.exit(2)
+            die('Not handling anything other than two heads merge.')
         try:
             h1 = firstBranch = sys.argv[nextArg + 1]
             h2 = secondBranch = sys.argv[nextArg + 2]
diff --git a/gitMergeCommon.py b/gitMergeCommon.py
--- a/gitMergeCommon.py
+++ b/gitMergeCommon.py
@@ -10,6 +10,10 @@ if sys.version_info[0] < 2 or \
 
 import subprocess
 
+def die(*args):
+    printList(args, sys.stderr)
+    sys.exit(2)
+
 # Debugging machinery
 # -------------------
 
@@ -28,11 +32,11 @@ def debug(*args):
         if funcName in functionsToDebug:
             printList(args)
 
-def printList(list):
+def printList(list, file=sys.stdout):
     for x in list:
-        sys.stdout.write(str(x))
-        sys.stdout.write(' ')
-    sys.stdout.write('\n')
+        file.write(str(x))
+        file.write(' ')
+    file.write('\n')
 
 # Program execution
 # -----------------

diff --git a/git-merge-fredrik.py b/git-merge-fredrik.py
--- a/git-merge-fredrik.py
+++ b/git-merge-fredrik.py
@@ -392,6 +392,9 @@ def usage():
 # This strategy module figures out merge bases itself, so we only
 # get heads.
 
+if len(sys.argv) < 4:
+    usage()
+
 for nextArg in xrange(1, len(sys.argv)):
     if sys.argv[nextArg] == '--':
         if len(sys.argv) != nextArg + 3:

diff --git a/gitMergeCommon.py b/gitMergeCommon.py
--- a/gitMergeCommon.py
+++ b/gitMergeCommon.py
@@ -46,6 +46,9 @@ class ProgramError(Exception):
         self.progStr = progStr
         self.error = error
 
+    def __str__(self):
+        return self.progStr + ': ' + self.error
+
 addDebug('runProgram')
 def runProgram(prog, input=None, returnCode=False, env=None, pipeOutput=True):
     debug('runProgram prog:', str(prog), 'input:', str(input))

.gitignore, Makefile, git-merge-fredrik.py, git-merge.sh

diff --git a/.gitignore b/.gitignore
--- a/.gitignore
+++ b/.gitignore
@@ -43,10 +43,10 @@ git-mailinfo
 git-mailsplit
 git-merge
 git-merge-base
-git-merge-fredrik
 git-merge-index
 git-merge-octopus
 git-merge-one-file
+git-merge-recursive
 git-merge-resolve
 git-merge-stupid
 git-mktag
diff --git a/Makefile b/Makefile
--- a/Makefile
+++ b/Makefile
@@ -83,7 +83,7 @@ SCRIPT_PERL = \
 	git-rename.perl git-shortlog.perl
 
 SCRIPT_PYTHON = \
-	git-merge-fredrik.py
+	git-merge-recursive.py
 
 # The ones that do not have to link with lcrypto nor lz.
 SIMPLE_PROGRAMS = \
diff --git a/git-merge-fredrik.py b/git-merge-recursive.py
similarity index 100%
rename from git-merge-fredrik.py
rename to git-merge-recursive.py
diff --git a/git-merge.sh b/git-merge.sh
--- a/git-merge.sh
+++ b/git-merge.sh
@@ -12,9 +12,9 @@ usage () {
     die "git-merge [-n] [-s <strategy>]... <merge-message> <head> <remote>+"
 }
 
-# all_strategies='resolve fredrik stupid octopus'
+# all_strategies='resolve recursive stupid octopus'
 
-all_strategies='fredrik octopus resolve stupid'
+all_strategies='recursive octopus resolve stupid'
 default_strategies='resolve octopus'
 use_strategies=