git-p4: convert path to unicode before processing them

P4 allows essentially arbitrary encoding for path data while we would
perfer to be dealing only with unicode strings.  Since path data need to
survive round-trip back to p4, this patch implements the general policy
that we store path data as-is, but decode them to unicode before doing
any non-trivial processing.

A new `decode_path()` method is provided that generally does the correct
conversion, taking into account `git-p4.pathEncoding` configuration.

For python2.7, path strings will be left as-is if it only contains ASCII
characters.

For python3, decoding is always done so that we have str objects.

Signed-off-by: Yang Zhao <yang.zhao@skyboxlabs.com>
Reviewed-by: Ben Keene <seraphire@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-p4.py

@@ -150,6 +150,21 @@ else:
     def encode_text_stream(s):
         return s.encode('utf_8') if isinstance(s, unicode) else s
 
+def decode_path(path):
+    """Decode a given string (bytes or otherwise) using configured path encoding options
+    """
+    encoding = gitConfig('git-p4.pathEncoding') or 'utf_8'
+    if bytes is not str:
+        return path.decode(encoding, errors='replace') if isinstance(path, bytes) else path
+    else:
+        try:
+            path.decode('ascii')
+        except:
+            path = path.decode(encoding, errors='replace')
+            if verbose:
+                print('Path with non-ASCII characters detected. Used {} to decode: {}'.format(encoding, path))
+        return path
+
 def write_pipe(c, stdin):
     if verbose:
         sys.stderr.write('Writing pipe: %s\n' % str(c))
@@ -697,7 +712,8 @@ def p4Where(depotPath):
         if "depotFile" in entry:
             # Search for the base client side depot path, as long as it starts with the branch's P4 path.
             # The base path always ends with "/...".
-            if entry["depotFile"].find(depotPath) == 0 and entry["depotFile"][-4:] == "/...":
+            entry_path = decode_path(entry['depotFile'])
+            if entry_path.find(depotPath) == 0 and entry_path[-4:] == "/...":
                 output = entry
                 break
         elif "data" in entry:
@@ -712,11 +728,11 @@ def p4Where(depotPath):
         return ""
     clientPath = ""
     if "path" in output:
-        clientPath = output.get("path")
+        clientPath = decode_path(output['path'])
     elif "data" in output:
         data = output.get("data")
-        lastSpace = data.rfind(" ")
-        clientPath = data[lastSpace + 1:]
+        lastSpace = data.rfind(b" ")
+        clientPath = decode_path(data[lastSpace + 1:])
 
     if clientPath.endswith("..."):
         clientPath = clientPath[:-3]
@@ -2484,7 +2500,7 @@ class View(object):
 
     def convert_client_path(self, clientFile):
         # chop off //client/ part to make it relative
-        if not clientFile.startswith(self.client_prefix):
+        if not decode_path(clientFile).startswith(self.client_prefix):
             die("No prefix '%s' on clientFile '%s'" %
                 (self.client_prefix, clientFile))
         return clientFile[len(self.client_prefix):]
@@ -2493,7 +2509,7 @@ class View(object):
         """ Caching file paths by "p4 where" batch query """
 
         # List depot file paths exclude that already cached
-        fileArgs = [f['path'] for f in files if f['path'] not in self.client_spec_path_cache]
+        fileArgs = [f['path'] for f in files if decode_path(f['path']) not in self.client_spec_path_cache]
 
         if len(fileArgs) == 0:
             return  # All files in cache
@@ -2508,16 +2524,18 @@ class View(object):
             if "unmap" in res:
                 # it will list all of them, but only one not unmap-ped
                 continue
+            depot_path = decode_path(res['depotFile'])
             if gitConfigBool("core.ignorecase"):
-                res['depotFile'] = res['depotFile'].lower()
-            self.client_spec_path_cache[res['depotFile']] = self.convert_client_path(res["clientFile"])
+                depot_path = depot_path.lower()
+            self.client_spec_path_cache[depot_path] = self.convert_client_path(res["clientFile"])
 
         # not found files or unmap files set to ""
         for depotFile in fileArgs:
+            depotFile = decode_path(depotFile)
             if gitConfigBool("core.ignorecase"):
                 depotFile = depotFile.lower()
             if depotFile not in self.client_spec_path_cache:
-                self.client_spec_path_cache[depotFile] = ""
+                self.client_spec_path_cache[depotFile] = b''
 
     def map_in_client(self, depot_path):
         """Return the relative location in the client where this
@@ -2635,7 +2653,7 @@ class P4Sync(Command, P4UserMap):
             elif path.lower() == p.lower():
                 return False
         for p in self.depotPaths:
-            if p4PathStartsWith(path, p):
+            if p4PathStartsWith(path, decode_path(p)):
                 return True
         return False
 
@@ -2644,7 +2662,7 @@ class P4Sync(Command, P4UserMap):
         fnum = 0
         while "depotFile%s" % fnum in commit:
             path =  commit["depotFile%s" % fnum]
-            found = self.isPathWanted(path)
+            found = self.isPathWanted(decode_path(path))
             if not found:
                 fnum = fnum + 1
                 continue
@@ -2678,7 +2696,7 @@ class P4Sync(Command, P4UserMap):
         if self.useClientSpec:
             # branch detection moves files up a level (the branch name)
             # from what client spec interpretation gives
-            path = self.clientSpecDirs.map_in_client(path)
+            path = decode_path(self.clientSpecDirs.map_in_client(path))
             if self.detectBranches:
                 for b in self.knownBranches:
                     if p4PathStartsWith(path, b + "/"):
@@ -2712,14 +2730,15 @@ class P4Sync(Command, P4UserMap):
         branches = {}
         fnum = 0
         while "depotFile%s" % fnum in commit:
-            path =  commit["depotFile%s" % fnum]
+            raw_path = commit["depotFile%s" % fnum]
+            path = decode_path(raw_path)
             found = self.isPathWanted(path)
             if not found:
                 fnum = fnum + 1
                 continue
 
             file = {}
-            file["path"] = path
+            file["path"] = raw_path
             file["rev"] = commit["rev%s" % fnum]
             file["action"] = commit["action%s" % fnum]
             file["type"] = commit["type%s" % fnum]
@@ -2728,7 +2747,7 @@ class P4Sync(Command, P4UserMap):
             # start with the full relative path where this file would
             # go in a p4 client
             if self.useClientSpec:
-                relPath = self.clientSpecDirs.map_in_client(path)
+                relPath = decode_path(self.clientSpecDirs.map_in_client(path))
             else:
                 relPath = self.stripRepoPath(path, self.depotPaths)
 
@@ -2766,14 +2785,15 @@ class P4Sync(Command, P4UserMap):
     # - helper for streamP4Files
 
     def streamOneP4File(self, file, contents):
-        relPath = self.stripRepoPath(file['depotFile'], self.branchPrefixes)
-        relPath = self.encodeWithUTF8(relPath)
+        file_path = file['depotFile']
+        relPath = self.stripRepoPath(decode_path(file_path), self.branchPrefixes)
+
         if verbose:
             if 'fileSize' in self.stream_file:
                 size = int(self.stream_file['fileSize'])
             else:
                 size = 0 # deleted files don't get a fileSize apparently
-            sys.stdout.write('\r%s --> %s (%i MB)\n' % (file['depotFile'], relPath, size/1024/1024))
+            sys.stdout.write('\r%s --> %s (%i MB)\n' % (file_path, relPath, size/1024/1024))
             sys.stdout.flush()
 
         (type_base, type_mods) = split_p4_type(file["type"])
@@ -2791,7 +2811,7 @@ class P4Sync(Command, P4UserMap):
                 # to nothing.  This causes p4 errors when checking out such
                 # a change, and errors here too.  Work around it by ignoring
                 # the bad symlink; hopefully a future change fixes it.
-                print("\nIgnoring empty symlink in %s" % file['depotFile'])
+                print("\nIgnoring empty symlink in %s" % file_path)
                 return
             elif data[-1] == '\n':
                 contents = [data[:-1]]
@@ -2810,7 +2830,7 @@ class P4Sync(Command, P4UserMap):
             # just the native "NT" type.
             #
             try:
-                text = p4_read_pipe(['print', '-q', '-o', '-', '%s@%s' % (file['depotFile'], file['change'])])
+                text = p4_read_pipe(['print', '-q', '-o', '-', '%s@%s' % (decode_path(file['depotFile']), file['change'])], raw=True)
             except Exception as e:
                 if 'Translation of file content failed' in str(e):
                     type_base = 'binary'
@@ -2818,7 +2838,7 @@ class P4Sync(Command, P4UserMap):
                     raise e
             else:
                 if p4_version_string().find('/NT') >= 0:
-                    text = text.replace('\r\n', '\n')
+                    text = text.replace(b'\r\n', b'\n')
                 contents = [ text ]
 
         if type_base == "apple":
@@ -2849,8 +2869,7 @@ class P4Sync(Command, P4UserMap):
         self.writeToGitStream(git_mode, relPath, contents)
 
     def streamOneP4Deletion(self, file):
-        relPath = self.stripRepoPath(file['path'], self.branchPrefixes)
-        relPath = self.encodeWithUTF8(relPath)
+        relPath = self.stripRepoPath(decode_path(file['path']), self.branchPrefixes)
         if verbose:
             sys.stdout.write("delete %s\n" % relPath)
             sys.stdout.flush()
@@ -3037,8 +3056,8 @@ class P4Sync(Command, P4UserMap):
         if self.clientSpecDirs:
             self.clientSpecDirs.update_client_spec_path_cache(files)
 
-        files = [f for f in files
-            if self.inClientSpec(f['path']) and self.hasBranchPrefix(f['path'])]
+        files = [f for (f, path) in ((f, decode_path(f['path'])) for f in files)
+            if self.inClientSpec(path) and self.hasBranchPrefix(path)]
 
         if gitConfigBool('git-p4.keepEmptyCommits'):
             allow_empty = True