git-changebar: Windows support possible

[eht16]

I recently built libgit2 on Windows. I will publish a ZIP archive soon (AFAIK there are no official Windows binary builds available).

There are only two issues I found so far:

• repository paths contain backslashes:

According to libgit2/libgit2#3012 libgit2 does not support backslashes as path seperator in repository paths. However, the current GCB code constructs the path of the file in the repository from the absolute file path and so on Windows it contains backslashes.
The following diff works for me though there is maybe a more elegant solution. It's a naive approach by simply replacing all backslashes by forward slashes:

diff --git a/git-changebar/src/gcb-plugin.c b/git-changebar/src/gcb-plugin.c
index 57afbcb..4db07b7 100644
--- a/git-changebar/src/gcb-plugin.c
+++ b/git-changebar/src/gcb-plugin.c
@@ -332,8 +332,17 @@ worker_thread (gpointer data)

     if (repo) {
       const gchar *relpath = path + strlen (git_repository_workdir (repo));
+#ifdef G_OS_WIN32
+      GString *repo_path = g_string_new(relpath);
+      /* relpath contains backslashes on Windows but libgit requires repository paths
+       * to be built of slashes, so replace them. */
+      utils_string_replace_all(repo_path, "\\", "/");
+#endif

-      job->blob = repo_get_file_blob (repo, relpath);
+      job->blob = repo_get_file_blob (repo, repo_path->str);
+#ifdef G_OS_WIN32
+      g_string_free(repo_path, TRUE);
+#endif
     } else {
       job->blob = NULL;
     }

• native EOL characters confuse the diff:

On Windows git repositories often use a setting which converts line endings in files to the native line ending characters. This confuses the generated diff and so all lines are marked as changed.
One could change that GIT setting but this could cause further troubles.
The best workaround I found so far is ignoring white space in the generated diff. This however is more than we want here because, AFAIU, this ignores any whitespace changes at the end of the line.
So I don't suggest to do this unconditionally but maybe a plugin setting could be added to let the user choose and a hint that this might be especially useful on Windows.
The option itself:

diff --git a/git-changebar/src/gcb-plugin.c b/git-changebar/src/gcb-plugin.c
index 57afbcb..4db07b7 100644
--- a/git-changebar/src/gcb-plugin.c
+++ b/git-changebar/src/gcb-plugin.c
@@ -547,7 +556,7 @@ diff_blob_to_doc (const git_blob   *old_blob,

   /* no context lines, and no need to bother about binary checks */
   opts.context_lines = 0;
-  opts.flags = GIT_DIFF_FORCE_TEXT;
+  opts.flags = GIT_DIFF_FORCE_TEXT | GIT_DIFF_IGNORE_WHITESPACE_EOL;

   ret = git_diff_blob_to_buffer (old_blob, NULL, buf, len, NULL, &opts,
                                  NULL, hunk_cb, NULL, payload);

I would take care to include the plugin and the libgit2 library in the Windows installer and related stuff.

[b4n]

First, thanks a lot for testing this on Windows!

Then, I spent quite some time trying to address both issues. Well, the first is relatively easy as you suggested, all what is needed is converting the paths (6a396b1). The EOL thing was a bit harder, but fortunately libgit2 has API for it too, so it only required a refactor to be able to use that (ee45caa). The only downside (if it is one), is that this requires libgit2 >= 0.21, so some older distributions won't be supported anymore -- but well, that's life.
Both are in https://github.com/b4n/geany-plugins/tree/git-changebar/content-filtered, could you please try it and see if it actually works as expected on Windows?

[b4n]

Okay, I successfully tested on Windows, paths seems to now work fine. Filters were tested on Linux, but should be the same on Windows.

Thanks!

[eht16]

Awesome! Thank you.

The filters also work on Windows, just tested.

P.S.: sorry for being so late :(.

[eht16]

JFTR: here is the promised Windows build of libgit2:
http://download.geany.org/contrib/libgit2-0.22.2.zip