simple euristic for further free packing improvements

diff --git a/git-merge-recursive.py b/git-merge-recursive.py
index f1320a69581500f3c70f0eb556e195a7e47e8714..ce8a31fda050f36b24b8dffa5ee29e7dde074963 100755 (executable)
--- a/git-merge-recursive.py
+++ b/git-merge-recursive.py
@@ -45,11 +45,10 @@ def setupIndex(temporary):
 # The entry point to the merge code
 # ---------------------------------
 
-def merge(h1, h2, branch1Name, branch2Name, graph, callDepth=0):
+def merge(h1, h2, branch1Name, branch2Name, graph, callDepth=0, ancestor=None):
     '''Merge the commits h1 and h2, return the resulting virtual
     commit object and a flag indicating the cleaness of the merge.'''
     assert(isinstance(h1, Commit) and isinstance(h2, Commit))
-    assert(isinstance(graph, Graph))
 
     global outputIndent
 
@@ -58,7 +57,11 @@ def merge(h1, h2, branch1Name, branch2Name, graph, callDepth=0):
     output(h2)
     sys.stdout.flush()
 
-    ca = getCommonAncestors(graph, h1, h2)
+    if ancestor:
+        ca = [ancestor]
+    else:
+        assert(isinstance(graph, Graph))
+        ca = getCommonAncestors(graph, h1, h2)
     output('found', len(ca), 'common ancestor(s):')
     for x in ca:
         output(x)
@@ -86,7 +89,7 @@ def merge(h1, h2, branch1Name, branch2Name, graph, callDepth=0):
     [shaRes, clean] = mergeTrees(h1.tree(), h2.tree(), mergedCA.tree(),
                                  branch1Name, branch2Name)
 
-    if clean or cacheOnly:
+    if graph and (clean or cacheOnly):
         res = Commit(None, [h1, h2], tree=shaRes)
         graph.addNode(res)
     else:
@@ -205,11 +208,16 @@ def mergeFile(oPath, oSha, oMode, aPath, aSha, aMode, bPath, bSha, bMode,
             orig = runProgram(['git-unpack-file', oSha]).rstrip()
             src1 = runProgram(['git-unpack-file', aSha]).rstrip()
             src2 = runProgram(['git-unpack-file', bSha]).rstrip()
-            [out, code] = runProgram(['merge',
-                                      '-L', branch1Name + '/' + aPath,
-                                      '-L', 'orig/' + oPath,
-                                      '-L', branch2Name + '/' + bPath,
-                                      src1, orig, src2], returnCode=True)
+            try:
+                [out, code] = runProgram(['merge',
+                                          '-L', branch1Name + '/' + aPath,
+                                          '-L', 'orig/' + oPath,
+                                          '-L', branch2Name + '/' + bPath,
+                                          src1, orig, src2], returnCode=True)
+            except ProgramError, e:
+                print >>sys.stderr, e
+                die("Failed to execute 'merge'. merge(1) is used as the "
+                    "file-level merge tool. Is 'merge' in your path?")
 
             sha = runProgram(['git-hash-object', '-t', 'blob', '-w',
                               src1]).rstrip()
@@ -283,12 +291,20 @@ def updateFileExt(sha, mode, path, updateCache, updateWd):
 def setIndexStages(path,
                    oSHA1, oMode,
                    aSHA1, aMode,
-                   bSHA1, bMode):
+                   bSHA1, bMode,
+                   clear=True):
+    istring = []
+    if clear:
+        istring.append("0 " + ("0" * 40) + "\t" + path + "\0")
+    if oMode:
+        istring.append("%o %s %d\t%s\0" % (oMode, oSHA1, 1, path))
+    if aMode:
+        istring.append("%o %s %d\t%s\0" % (aMode, aSHA1, 2, path))
+    if bMode:
+        istring.append("%o %s %d\t%s\0" % (bMode, bSHA1, 3, path))
+
     runProgram(['git-update-index', '-z', '--index-info'],
-               input="0 " + ("0" * 40) + "\t" + path + "\0" + \
-               "%o %s %d\t%s\0" % (oMode, oSHA1, 1, path) + \
-               "%o %s %d\t%s\0" % (aMode, aSHA1, 2, path) + \
-               "%o %s %d\t%s\0" % (bMode, bSHA1, 3, path))
+               input="".join(istring))
 
 def removeFile(clean, path):
     updateCache = cacheOnly or clean
@@ -570,7 +586,7 @@ def processRenames(renamesA, renamesB, branchNameA, branchNameB):
             continue
 
         ren1.processed = True
-        removeFile(True, ren1.srcName)
+
         if ren2:
             # Renamed in 1 and renamed in 2
             assert(ren1.srcName == ren2.srcName)
@@ -598,13 +614,19 @@ def processRenames(renamesA, renamesB, branchNameA, branchNameB):
                            'adding as', dstName2, 'instead.')
                     removeFile(False, ren2.dstName)
                 else:
-                    dstName2 = ren1.dstName
+                    dstName2 = ren2.dstName
+                setIndexStages(dstName1,
+                               None, None,
+                               ren1.dstSha, ren1.dstMode,
+                              None, None)
+                setIndexStages(dstName2,
+                               None, None,
+                               None, None,
+                               ren2.dstSha, ren2.dstMode)
 
-                # NEEDSWORK: place dstNameA at stage 2 and dstNameB at stage 3
-                # What about other stages???
-                updateFile(False, ren1.dstSha, ren1.dstMode, dstName1)
-                updateFile(False, ren2.dstSha, ren2.dstMode, dstName2)
             else:
+                removeFile(True, ren1.srcName)
+
                 [resSha, resMode, clean, merge] = \
                          mergeFile(ren1.srcName, ren1.srcSha, ren1.srcMode,
                                    ren1.dstName, ren1.dstSha, ren1.dstMode,
@@ -630,6 +652,8 @@ def processRenames(renamesA, renamesB, branchNameA, branchNameB):
 
                 updateFile(clean, resSha, resMode, ren1.dstName)
         else:
+            removeFile(True, ren1.srcName)
+
             # Renamed in 1, maybe changed in 2
             if renamesA == renames1:
                 stage = 3
@@ -870,12 +894,11 @@ def usage():
 
 # main entry point as merge strategy module
 # The first parameters up to -- are merge bases, and the rest are heads.
-# This strategy module figures out merge bases itself, so we only
-# get heads.
 
 if len(sys.argv) < 4:
     usage()
 
+bases = []
 for nextArg in xrange(1, len(sys.argv)):
     if sys.argv[nextArg] == '--':
         if len(sys.argv) != nextArg + 3:
@@ -886,6 +909,8 @@ def usage():
         except IndexError:
             usage()
         break
+    else:
+        bases.append(sys.argv[nextArg])
 
 print 'Merging', h1, 'with', h2
 
@@ -893,10 +918,17 @@ def usage():
     h1 = runProgram(['git-rev-parse', '--verify', h1 + '^0']).rstrip()
     h2 = runProgram(['git-rev-parse', '--verify', h2 + '^0']).rstrip()
 
-    graph = buildGraph([h1, h2])
-
-    [dummy, clean] = merge(graph.shaMap[h1], graph.shaMap[h2],
-                           firstBranch, secondBranch, graph)
+    if len(bases) == 1:
+        base = runProgram(['git-rev-parse', '--verify',
+                           bases[0] + '^0']).rstrip()
+        ancestor = Commit(base, None)
+        [dummy, clean] = merge(Commit(h1, None), Commit(h2, None),
+                               firstBranch, secondBranch, None, 0,
+                               ancestor)
+    else:
+        graph = buildGraph([h1, h2])
+        [dummy, clean] = merge(graph.shaMap[h1], graph.shaMap[h2],
+                               firstBranch, secondBranch, graph)
 
     print ''
 except: