git-p4: Clean up git-p4 submit's log message handling.

Instead of trying to substitute fields in the p4 submit template we now simply
replace the description of the submit with the log message of the git commit.

Signed-off-by: Simon Hausmann <simon@lst.de>

contrib/fast-import/git-p4

@@ -483,10 +483,6 @@ class P4Submit(Command):
         self.verbose = False
         self.isWindows = (platform.system() == "Windows")
 
-        self.logSubstitutions = {}
-        self.logSubstitutions["<enter description here>"] = "%log%"
-        self.logSubstitutions["\tDetails:"] = "\tDetails:  %log%"
-
     def check(self):
         if len(p4CmdList("opened ...")) > 0:
             die("You have files opened with perforce! Close them before starting the sync.")
@@ -507,26 +503,31 @@ class P4Submit(Command):
 
         self.config["commits"] = commits
 
+    # replaces everything between 'Description:' and the next P4 submit template field with the
+    # commit message
     def prepareLogMessage(self, template, message):
         result = ""
 
+        inDescriptionSection = False
+
         for line in template.split("\n"):
             if line.startswith("#"):
                 result += line + "\n"
                 continue
 
-            substituted = False
-            for key in self.logSubstitutions.keys():
-                if line.find(key) != -1:
-                    value = self.logSubstitutions[key]
-                    value = value.replace("%log%", message)
-                    if value != "@remove@":
-                        result += line.replace(key, value) + "\n"
-                    substituted = True
-                    break
+            if inDescriptionSection:
+                if line.startswith("Files:"):
+                    inDescriptionSection = False
+                else:
+                    continue
+            else:
+                if line.startswith("Description:"):
+                    inDescriptionSection = True
+                    line += "\n"
+                    for messageLine in message.split("\n"):
+                        line += "\t" + messageLine + "\n"
 
-            if not substituted:
-                result += line + "\n"
+            result += line + "\n"
 
         return result
 
@@ -650,7 +651,6 @@ class P4Submit(Command):
         logMessage = ""
         if not self.directSubmit:
             logMessage = extractLogMessageFromGitCommit(id)
-            logMessage = logMessage.replace("\n", "\n\t")
             if self.isWindows:
                 logMessage = logMessage.replace("\n", "\r\n")
             logMessage = logMessage.strip()