Merge branch 'ld/git-p4-expanded-keywords'

* ld/git-p4-expanded-keywords:
  : Teach git-p4 to unexpand $RCS$-like keywords that are embedded in
  : tracked contents in order to reduce unnecessary merge conflicts.
  git-p4: add initial support for RCS keywords

Documentation/git-p4.txt

@@ -483,6 +483,11 @@ git-p4.skipUserNameCheck::
 	user map, 'git p4' exits.  This option can be used to force
 	submission regardless.
 
+git-p4.attemptRCSCleanup:
+    If enabled, 'git p4 submit' will attempt to cleanup RCS keywords
+    ($Header$, etc). These would otherwise cause merge conflicts and prevent
+    the submit going ahead. This option should be considered experimental at
+    present.
 
 IMPLEMENTATION DETAILS
 ----------------------

contrib/fast-import/git-p4

@@ -10,7 +10,7 @@
 
 import optparse, sys, os, marshal, subprocess, shelve
 import tempfile, getopt, os.path, time, platform
-import re
+import re, shutil
 
 verbose = False
 
@@ -186,6 +186,47 @@ def split_p4_type(p4type):
         mods = s[1]
     return (base, mods)
 
+#
+# return the raw p4 type of a file (text, text+ko, etc)
+#
+def p4_type(file):
+    results = p4CmdList(["fstat", "-T", "headType", file])
+    return results[0]['headType']
+
+#
+# Given a type base and modifier, return a regexp matching
+# the keywords that can be expanded in the file
+#
+def p4_keywords_regexp_for_type(base, type_mods):
+    if base in ("text", "unicode", "binary"):
+        kwords = None
+        if "ko" in type_mods:
+            kwords = 'Id|Header'
+        elif "k" in type_mods:
+            kwords = 'Id|Header|Author|Date|DateTime|Change|File|Revision'
+        else:
+            return None
+        pattern = r"""
+            \$              # Starts with a dollar, followed by...
+            (%s)            # one of the keywords, followed by...
+            (:[^$]+)?       # possibly an old expansion, followed by...
+            \$              # another dollar
+            """ % kwords
+        return pattern
+    else:
+        return None
+
+#
+# Given a file, return a regexp matching the possible
+# RCS keywords that will be expanded, or None for files
+# with kw expansion turned off.
+#
+def p4_keywords_regexp_for_file(file):
+    if not os.path.exists(file):
+        return None
+    else:
+        (type_base, type_mods) = split_p4_type(p4_type(file))
+        return p4_keywords_regexp_for_type(type_base, type_mods)
 
 def setP4ExecBit(file, mode):
     # Reopens an already open file and changes the execute bit to match
@@ -753,6 +794,29 @@ class P4Submit(Command, P4UserMap):
 
         return result
 
+    def patchRCSKeywords(self, file, pattern):
+        # Attempt to zap the RCS keywords in a p4 controlled file matching the given pattern
+        (handle, outFileName) = tempfile.mkstemp(dir='.')
+        try:
+            outFile = os.fdopen(handle, "w+")
+            inFile = open(file, "r")
+            regexp = re.compile(pattern, re.VERBOSE)
+            for line in inFile.readlines():
+                line = regexp.sub(r'$\1$', line)
+                outFile.write(line)
+            inFile.close()
+            outFile.close()
+            # Forcibly overwrite the original file
+            os.unlink(file)
+            shutil.move(outFileName, file)
+        except:
+            # cleanup our temporary file
+            os.unlink(outFileName)
+            print "Failed to strip RCS keywords in %s" % file
+            raise
+
+        print "Patched up RCS keywords in %s" % file
+
     def p4UserForCommit(self,id):
         # Return the tuple (perforce user,git email) for a given git commit id
         self.getUserMapFromPerforceServer()
@@ -918,6 +982,7 @@ class P4Submit(Command, P4UserMap):
         filesToDelete = set()
         editedFiles = set()
         filesToChangeExecBit = {}
+
         for line in diff:
             diff = parseDiffTreeEntry(line)
             modifier = diff['status']
@@ -964,9 +1029,45 @@ class P4Submit(Command, P4UserMap):
         patchcmd = diffcmd + " | git apply "
         tryPatchCmd = patchcmd + "--check -"
         applyPatchCmd = patchcmd + "--check --apply -"
+        patch_succeeded = True
 
         if os.system(tryPatchCmd) != 0:
+            fixed_rcs_keywords = False
+            patch_succeeded = False
             print "Unfortunately applying the change failed!"
+
+            # Patch failed, maybe it's just RCS keyword woes. Look through
+            # the patch to see if that's possible.
+            if gitConfig("git-p4.attemptRCSCleanup","--bool") == "true":
+                file = None
+                pattern = None
+                kwfiles = {}
+                for file in editedFiles | filesToDelete:
+                    # did this file's delta contain RCS keywords?
+                    pattern = p4_keywords_regexp_for_file(file)
+
+                    if pattern:
+                        # this file is a possibility...look for RCS keywords.
+                        regexp = re.compile(pattern, re.VERBOSE)
+                        for line in read_pipe_lines(["git", "diff", "%s^..%s" % (id, id), file]):
+                            if regexp.search(line):
+                                if verbose:
+                                    print "got keyword match on %s in %s in %s" % (pattern, line, file)
+                                kwfiles[file] = pattern
+                                break
+
+                for file in kwfiles:
+                    if verbose:
+                        print "zapping %s with %s" % (line,pattern)
+                    self.patchRCSKeywords(file, kwfiles[file])
+                    fixed_rcs_keywords = True
+
+            if fixed_rcs_keywords:
+                print "Retrying the patch with RCS keywords cleaned up"
+                if os.system(tryPatchCmd) == 0:
+                    patch_succeeded = True
+
+        if not patch_succeeded:
             print "What do you want to do?"
             response = "x"
             while response != "s" and response != "a" and response != "w":
@@ -1585,15 +1686,12 @@ class P4Sync(Command, P4UserMap):
 
         # Note that we do not try to de-mangle keywords on utf16 files,
         # even though in theory somebody may want that.
-        if type_base in ("text", "unicode", "binary"):
-            if "ko" in type_mods:
-                text = ''.join(contents)
-                text = re.sub(r'\$(Id|Header):[^$]*\$', r'$\1$', text)
-                contents = [ text ]
-            elif "k" in type_mods:
-                text = ''.join(contents)
-                text = re.sub(r'\$(Id|Header|Author|Date|DateTime|Change|File|Revision):[^$]*\$', r'$\1$', text)
-                contents = [ text ]
+        pattern = p4_keywords_regexp_for_type(type_base, type_mods)
+        if pattern:
+            regexp = re.compile(pattern, re.VERBOSE)
+            text = ''.join(contents)
+            text = regexp.sub(r'$\1$', text)
+            contents = [ text ]
 
         self.gitStream.write("M %s inline %s\n" % (git_mode, relPath))