Cloud storage: make user visible messages more consistent

I hate this patch. But it makes no sense to expose users to git level
error messages. So this is trying to make things much easier (and,
frankly, less informative) if we are accessing the Subsurface cloud.

The way this is implemented is really ugly; it tries to avoid frequent
repetition of the same strings by using different exit points for the
functions in question. I'm not convinced this was the best way to do it
but it's what I have.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

git-access.c

@@ -45,6 +45,8 @@
 	git_branch_create(out, repo, branch_name, target, force)
 #endif
 
+bool is_subsurface_cloud = false;
+
 int (*update_progress_cb)(int) = NULL;
 
 void set_git_update_cb(int(*cb)(int))
@@ -113,7 +115,10 @@ static int check_clean(const char *path, unsigned int status, void *payload)
 	status &= ~GIT_STATUS_CURRENT | GIT_STATUS_IGNORED;
 	if (!status)
 		return 0;
-	report_error("WARNING: Git cache directory modified (path %s) status %0x", path, status);
+	if (is_subsurface_cloud)
+		report_error(translate("gettextFromC", "Local cache directory %s corrupted - can't sync with Subsurface cloud storage"), path);
+	else
+		report_error("WARNING: Git cache directory modified (path %s) status %0x", path, status);
 	return 1;
 }
 
@@ -131,26 +136,34 @@ static int reset_to_remote(git_repository *repo, git_reference *local, const git
 		git_reference *out;
 
 		if (git_reference_set_target(&out, local, new_id, "Update to remote"))
-			return report_error("Could not update local ref to newer remote ref");
+			return report_error(translate("gettextFromC", "Could not update local cache to newer remote data"));
 
 		git_reference_free(out);
 
+#ifdef DEBUG
 		// Not really an error, just informational
 		report_error("Updated local branch from remote");
-
+#endif
 		return 0;
 	}
 
-	if (git_object_lookup(&target, repo, new_id, GIT_OBJ_COMMIT))
+	if (git_object_lookup(&target, repo, new_id, GIT_OBJ_COMMIT)) {
-		return report_error("Could not look up remote commit");
+		if (is_subsurface_cloud)
-
+			return report_error(translate("gettextFromC", "Subsurface cloud storage corrupted"));
+		else
+			return report_error("Could not look up remote commit");
+	}
 	opts.checkout_strategy = GIT_CHECKOUT_SAFE;
-	if (git_reset(repo, target, GIT_RESET_HARD, &opts))
+	if (git_reset(repo, target, GIT_RESET_HARD, &opts)) {
-		return report_error("Local head checkout failed after update");
+		if (is_subsurface_cloud)
-
+			return report_error(translate("gettextFromC", "Could not update local cache to newer remote data"));
+		else
+			return report_error("Local head checkout failed after update");
+	}
 	// Not really an error, just informational
+#ifdef DEBUG
 	report_error("Updated local information from remote");
-
+#endif
 	return 0;
 }
 
@@ -217,9 +230,12 @@ static int update_remote(git_repository *repo, git_remote *origin, git_reference
 		opts.callbacks.credentials = credential_https_cb;
 	opts.callbacks.certificate_check = certificate_check_cb;
 #endif
-	if (git_remote_push(origin, &refspec, &opts))
+	if (git_remote_push(origin, &refspec, &opts)) {
-		return report_error("Unable to update remote with current local cache state (%s)", giterr_last()->message);
+		if (is_subsurface_cloud)
-
+			return report_error(translate("gettextFromC", "Could not update Subsurface cloud storage, try again later"));
+		else
+			return report_error("Unable to update remote with current local cache state (%s)", giterr_last()->message);
+	}
 	return 0;
 }
 
@@ -248,20 +264,35 @@ static int try_to_git_merge(git_repository *repo, git_reference *local, git_refe
 #endif
 	merge_options.file_favor = GIT_MERGE_FILE_FAVOR_UNION;
 	merge_options.rename_threshold = 100;
-	if (git_commit_lookup(&local_commit, repo, local_id))
+	if (git_commit_lookup(&local_commit, repo, local_id)) {
-		return report_error(translate("gettextFromC", "Remote storage and local data diverged. Error: can't get commit (%s)"), giterr_last()->message);
+		fprintf(stderr, "Remote storage and local data diverged. Error: can't get commit (%s)", giterr_last()->message);
-	if (git_commit_tree(&local_tree, local_commit))
+		goto diverged_error;
-		return report_error(translate("gettextFromC", "Remote storage and local data diverged. Error: failed local tree lookup (%s)"), giterr_last()->message);
+	}
-	if (git_commit_lookup(&remote_commit, repo, remote_id))
+	if (git_commit_tree(&local_tree, local_commit)) {
-		return report_error(translate("gettextFromC", "Remote storage and local data diverged. Error: can't get commit (%s)"), giterr_last()->message);
+		fprintf(stderr, "Remote storage and local data diverged. Error: failed local tree lookup (%s)", giterr_last()->message);
-	if (git_commit_tree(&remote_tree, remote_commit))
+		goto diverged_error;
-		return report_error(translate("gettextFromC", "Remote storage and local data diverged. Error: failed remote tree lookup (%s)"), giterr_last()->message);
+	}
-	if (git_commit_lookup(&base_commit, repo, base))
+	if (git_commit_lookup(&remote_commit, repo, remote_id)) {
-		return report_error(translate("gettextFromC", "Remote storage and local data diverged. Error: can't get commit: (%s)"), giterr_last()->message);
+		fprintf(stderr, "Remote storage and local data diverged. Error: can't get commit (%s)", giterr_last()->message);
-	if (git_commit_tree(&base_tree, base_commit))
+		goto diverged_error;
-		return report_error(translate("gettextFromC", "Remote storage and local data diverged. Error: failed base tree lookup: (%s)"), giterr_last()->message);
+	}
-	if (git_merge_trees(&merged_index, repo, base_tree, local_tree, remote_tree, &merge_options))
+	if (git_commit_tree(&remote_tree, remote_commit)) {
+		fprintf(stderr, "Remote storage and local data diverged. Error: failed local tree lookup (%s)", giterr_last()->message);
+		goto diverged_error;
+	}
+	if (git_commit_lookup(&base_commit, repo, base)) {
+		fprintf(stderr, "Remote storage and local data diverged. Error: can't get commit (%s)", giterr_last()->message);
+		goto diverged_error;
+	}
+	if (git_commit_tree(&base_tree, base_commit)) {
+		fprintf(stderr, "Remote storage and local data diverged. Error: failed base tree lookup (%s)", giterr_last()->message);
+		goto diverged_error;
+	}
+	if (git_merge_trees(&merged_index, repo, base_tree, local_tree, remote_tree, &merge_options)) {
+		fprintf(stderr, "Remote storage and local data diverged. Error: merge failed (%s)", giterr_last()->message);
+		// this is the one where I want to report more detail to the user - can't quite explain why
 		return report_error(translate("gettextFromC", "Remote storage and local data diverged. Error: merge failed (%s)"), giterr_last()->message);
+	}
 	if (git_index_has_conflicts(merged_index)) {
 		int error;
 		const git_index_entry *ancestor = NULL,
@@ -290,7 +321,7 @@ static int try_to_git_merge(git_repository *repo, git_reference *local, git_refe
 		}
 		git_index_conflict_cleanup(merged_index);
 		git_index_conflict_iterator_free(iter);
-		report_error(translate("gettextFromC", "Remote storage and local data diverged. Error: merge conflict - manual intervention needed"));
+		report_error(translate("gettextFromC", "Remote storage and local data diverged. Cannot combine local and remote changes"));
 	}
 	git_oid merge_oid, commit_oid;
 	git_tree *merged_tree;
@@ -298,28 +329,35 @@ static int try_to_git_merge(git_repository *repo, git_reference *local, git_refe
 	git_commit *commit;
 
 	if (git_index_write_tree_to(&merge_oid, merged_index, repo))
-		return report_error(translate("gettextFromC", "Remote storage and local data diverged. Error: writing the tree failed (%s)"), giterr_last()->message);
+		goto write_error;
 	if (git_tree_lookup(&merged_tree, repo, &merge_oid))
-		return report_error(translate("gettextFromC", "Remote storage and local data diverged. Error: tree lookup failed (%s)"), giterr_last()->message);
+		goto write_error;
 	if (git_signature_default(&author, repo) < 0)
-		return report_error(translate("gettextFromC", "Failed to get author: (%s)"), giterr_last()->message);
+		if (git_signature_now(&author, "Subsurface", "noemail@given") < 0)
+			goto write_error;
 	if (git_commit_create_v(&commit_oid, repo, NULL, author, author, NULL, "automatic merge", merged_tree, 2, local_commit, remote_commit))
-		return report_error(translate("gettextFromC", "Remote storage and local data diverged. Error: git commit create failed (%s)"), giterr_last()->message);
+		goto write_error;
 	if (git_commit_lookup(&commit, repo, &commit_oid))
-		return report_error(translate("gettextFromC", "Error: could not lookup the merge commit I just created (%s)"), giterr_last()->message);
+		goto write_error;
 	if (git_branch_is_head(local) && !git_repository_is_bare(repo)) {
 		git_object *parent;
 		git_reference_peel(&parent, local, GIT_OBJ_COMMIT);
 		if (update_git_checkout(repo, parent, merged_tree)) {
-			report_error("Warning: checked out branch is inconsistent with git data");
+			goto write_error;
 		}
 	}
 	if (git_reference_set_target(&local, local, &commit_oid, "Subsurface merge event"))
-		return report_error("Error: failed to update branch (%s)", giterr_last()->message);
+		goto write_error;
 	set_git_id(&commit_oid);
 	git_signature_free(author);
 
 	return 0;
+
+diverged_error:
+	return report_error(translate("gettextFromC", "Remote storage and local data diverged"));
+
+write_error:
+	return report_error(translate("gettextFromC", "Remote storage and local data diverged. Error: writing the data failed (%s)"), giterr_last()->message);
 }
 
 static int try_to_update(git_repository *repo, git_remote *origin, git_reference *local, git_reference *remote, enum remote_transport rt)
@@ -332,18 +370,27 @@ static int try_to_update(git_repository *repo, git_remote *origin, git_reference
 
 	// Dirty modified state in the working tree? We're not going
 	// to update either way
-	if (git_status_foreach(repo, check_clean, NULL))
+	if (git_status_foreach(repo, check_clean, NULL)) {
-		return report_error("local cached copy is dirty, skipping update");
+		if (is_subsurface_cloud)
-
+			goto cloud_data_error;
+		else
+			return report_error("local cached copy is dirty, skipping update");
+	}
 	local_id = git_reference_target(local);
 	remote_id = git_reference_target(remote);
 
-	if (!local_id || !remote_id)
+	if (!local_id || !remote_id) {
-		return report_error("Unable to get local or remote SHA1");
+		if (is_subsurface_cloud)
-
+			goto cloud_data_error;
-	if (git_merge_base(&base, repo, local_id, remote_id))
+		else
-		return report_error("Unable to find common commit of local and remote branches");
+			return report_error("Unable to get local or remote SHA1");
-
+	}
+	if (git_merge_base(&base, repo, local_id, remote_id)) {
+		if (is_subsurface_cloud)
+			goto cloud_data_error;
+		else
+			return report_error("Unable to find common commit of local and remote branches");
+	}
 	/* Is the remote strictly newer? Use it */
 	if (git_oid_equal(&base, local_id))
 		return reset_to_remote(repo, local, remote_id);
@@ -353,15 +400,25 @@ static int try_to_update(git_repository *repo, git_remote *origin, git_reference
 		return update_remote(repo, origin, local, remote, rt);
 
 	/* Merging a bare repository always needs user action */
-	if (git_repository_is_bare(repo))
+	if (git_repository_is_bare(repo)) {
-		return report_error("Local and remote have diverged, merge of bare branch needed");
+		if (is_subsurface_cloud)
-
+			goto cloud_data_error;
+		else
+			return report_error("Local and remote have diverged, merge of bare branch needed");
+	}
 	/* Merging will definitely need the head branch too */
-	if (git_branch_is_head(local) != 1)
+	if (git_branch_is_head(local) != 1) {
-		return report_error("Local and remote do not match, local branch not HEAD - cannot update");
+		if (is_subsurface_cloud)
-
+			goto cloud_data_error;
+		else
+			return report_error("Local and remote do not match, local branch not HEAD - cannot update");
+	}
 	/* Ok, let's try to merge these */
 	return try_to_git_merge(repo, local, remote, &base, local_id, remote_id);
+
+cloud_data_error:
+	return report_error(translate("gettextFromC", "Problems with local cache of Subsurface cloud data"));
+
 }
 
 static int check_remote_status(git_repository *repo, git_remote *origin, const char *branch, enum remote_transport rt)
@@ -370,9 +427,12 @@ static int check_remote_status(git_repository *repo, git_remote *origin, const c
 
 	git_reference *local_ref, *remote_ref;
 
-	if (git_branch_lookup(&local_ref, repo, branch, GIT_BRANCH_LOCAL))
+	if (git_branch_lookup(&local_ref, repo, branch, GIT_BRANCH_LOCAL)) {
-		return report_error("Git cache branch %s no longer exists", branch);
+		if (is_subsurface_cloud)
-
+			report_error(translate("gettextFromC", "Problems with local cache of Subsurface cloud data"));
+		else
+			return report_error("Git cache branch %s no longer exists", branch);
+	}
 	if (git_branch_upstream(&remote_ref, local_ref)) {
 		/* so there is no upstream branch for our branch; that's a problem.
 		 * let's push our branch */
@@ -421,8 +481,8 @@ int sync_with_remote(git_repository *repo, const char *remote, const char *branc
 	 */
 	error = git_remote_lookup(&origin, repo, "origin");
 	if (error) {
-		report_error("Repository '%s' origin lookup failed (%s)",
+		if (!is_subsurface_cloud)
-			remote, giterr_last()->message);
+			report_error("Repository '%s' origin lookup failed (%s)", remote, giterr_last()->message);
 		return 0;
 	}
 
@@ -445,7 +505,8 @@ int sync_with_remote(git_repository *repo, const char *remote, const char *branc
 #endif
 	// NOTE! A fetch error is not fatal, we just report it
 	if (error) {
-		report_error("Unable to fetch remote '%s'", remote);
+		if (!is_subsurface_cloud)
+			report_error("Unable to fetch remote '%s'", remote);
 		error = 0;
 	} else {
 		error = check_remote_status(repo, origin, branch, rt);
@@ -461,8 +522,10 @@ static git_repository *update_local_repo(const char *localdir, const char *remot
 
 	error = git_repository_open(&repo, localdir);
 	if (error) {
-		report_error("Unable to open git cache repository at %s: %s",
+		if (is_subsurface_cloud)
-			localdir, giterr_last()->message);
+			report_error(translate("gettextFromC", "Problems with local cache of Subsurface cloud data"));
+		else
+			report_error("Unable to open git cache repository at %s: %s", localdir, giterr_last()->message);
 		return NULL;
 	}
 	sync_with_remote(repo, remote, branch, rt);
@@ -551,7 +614,7 @@ static git_repository *create_local_repo(const char *localdir, const char *remot
 			 * So we need to create the branch and push it to the remote */
 			cloned_repo = create_and_push_remote(localdir, remote, branch);
 #if !defined(DEBUG)
-		} else if (strstr(remote, prefs.cloud_git_url)) {
+		} else if (is_subsurface_cloud) {
 			report_error(translate("gettextFromC", "Error connecting to Subsurface cloud storage"));
 #endif
 		} else {
@@ -578,7 +641,10 @@ static struct git_repository *get_remote_repo(const char *localdir, const char *
 	/* Do we already have a local cache? */
 	if (!stat(localdir, &st)) {
 		if (!S_ISDIR(st.st_mode)) {
-			report_error("local git cache at '%s' is corrupt");
+			if (is_subsurface_cloud)
+				report_error(translate("gettextFromC", "Problems with local cache of Subsurface cloud data"));
+			else
+				report_error("local git cache at '%s' is corrupt");
 			return NULL;
 		}
 		return update_local_repo(localdir, remote, branch, rt);
@@ -659,6 +725,10 @@ static struct git_repository *is_remote_git_repository(char *remote, const char
 	if (!localdir)
 		return NULL;
 
+	/* remember if the current git storage we are working on is our cloud storage
+	 * this is used to create more user friendly error message and warnings */
+	is_subsurface_cloud = strstr(remote, prefs.cloud_git_url) != NULL;
+
 	return get_remote_repo(localdir, remote, branch);
 }