cloudstorage: update remote if cloud server changes

If we can't reach the cloud server in the URL (which might come from the
settings or be passed in by the user), we try the alternative server(s).
If we end up changing servers, we need to update the remote that we have
already parsed from the URL.

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

3 files changed, 26 insertions, 14 deletions

diff --git a/core/checkcloudconnection.cpp b/core/checkcloudconnection.cpp
index 05e529b90..b8e9fc26f 100644
--- a/core/checkcloudconnection.cpp
+++ b/core/checkcloudconnection.cpp
@@ -11,6 +11,7 @@
 #include "git-access.h"
 #include "errorhelper.h"
 #include "core/subsurface-string.h"
+#include "core/membuffer.h"
 #include "core/settings/qPrefCloudStorage.h"
 
 #include "checkcloudconnection.h"
@@ -197,9 +198,20 @@ void CheckCloudConnection::gotContinent(QNetworkReply *reply)
 }
 
 // helper to be used from C code
-extern "C" bool canReachCloudServer()
+extern "C" bool canReachCloudServer(const char **remote)
 {
 	if (verbose)
-		qWarning() << "Cloud storage: checking connection to cloud server";
-	return CheckCloudConnection().checkServer();
+		qWarning() << "Cloud storage: checking connection to cloud server" << *remote;
+	bool connection = CheckCloudConnection().checkServer();
+	if (strstr(*remote, prefs.cloud_base_url) == nullptr) {
+		// we switched the cloud URL - likely because we couldn't reach the server passed in
+		// the strstr with the offset is designed so we match the right component in the name;
+		// the cloud_base_url ends with a '/', so we need the text starting at "git/..."
+		char *newremote = format_string("%s%s", prefs.cloud_base_url, strstr(*remote, "org/git/") + 4);
+		if (verbose)
+			qDebug() << "updating remote to: " << newremote;
+		free((void*)*remote);
+		*remote = newremote;
+	}
+	return connection;
 }
diff --git a/core/git-access.c b/core/git-access.c
index c66a24a5d..4b8762749 100644
--- a/core/git-access.c
+++ b/core/git-access.c
@@ -718,7 +718,7 @@ int sync_with_remote(git_repository *repo, const char *remote, const char *branc
 
 	// we know that we already checked for the cloud server, but to give a decent warning message
 	// here in case none of them are reachable, let's check one more time
-	if (is_subsurface_cloud && !canReachCloudServer()) {
+	if (is_subsurface_cloud && !canReachCloudServer(&remote)) {
 		// this is not an error, just a warning message, so return 0
 		SSRF_INFO("git storage: cannot connect to remote server");
 		report_error("Cannot connect to cloud server, working with local copy");
@@ -889,7 +889,7 @@ static git_repository *create_local_repo(const char *localdir, const char *remot
 	opts.fetch_opts.callbacks.certificate_check = certificate_check_cb;
 
 	opts.checkout_branch = branch;
-	if (is_subsurface_cloud && !canReachCloudServer()) {
+	if (is_subsurface_cloud && !canReachCloudServer(&remote)) {
 		SSRF_INFO("git storage: cannot reach remote server");
 		return 0;
 	}
@@ -985,10 +985,10 @@ static struct git_repository *get_remote_repo(const char *localdir, const char *
  *    https://host/repo[branch]
  *    file://repo[branch]
  */
-static struct git_repository *is_remote_git_repository(char *remote, const char *branch)
+static struct git_repository *is_remote_git_repository(char **remote, const char *branch)
 {
 	char c, *localdir;
-	char *p = remote;
+	char *p = *remote;
 
 	while ((c = *p++) >= 'a' && c <= 'z')
 		/* nothing */;
@@ -1024,7 +1024,7 @@ static struct git_repository *is_remote_git_repository(char *remote, const char
 	 * next we need to make sure that any encoded username
 	 * has been extracted from the URL
 	 */
-	char *at = strchr(remote, '@');
+	char *at = strchr(*remote, '@');
 	if (at) {
 		/* was this the @ that denotes an account? that means it was before the
 		 * first '/' after the protocol:// - so let's find a '/' after that and compare */
@@ -1037,13 +1037,13 @@ static struct git_repository *is_remote_git_repository(char *remote, const char
 			memmove(p, at + 1, strlen(at + 1) + 1);
 		}
 	}
-	localdir = get_local_dir(remote, branch);
+	localdir = get_local_dir(*remote, branch);
 	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_base_url) != NULL;
+	is_subsurface_cloud = strstr(*remote, prefs.cloud_base_url) != NULL;
 
 	/* if we are planning to access the server, make sure it's available and try to
 	 * pick one of the alternative servers if necessary */
@@ -1051,9 +1051,9 @@ static struct git_repository *is_remote_git_repository(char *remote, const char
 		// since we know that this is Subsurface cloud storage, we don't have to
 		// worry about the local directory name changing if we end up with a different
 		// cloud_base_url... the algorithm normalizes those URLs
-		(void)canReachCloudServer();
+		(void)canReachCloudServer((const char **)remote);
 	}
-	return get_remote_repo(localdir, remote, branch);
+	return get_remote_repo(localdir, *remote, branch);
 }
 
 /*
@@ -1127,7 +1127,7 @@ struct git_repository *is_git_repository(const char *filename, const char **bran
 		*remote = loc;
 		return dummy_git_repository;
 	}
-	repo = is_remote_git_repository(loc, branch);
+	repo = is_remote_git_repository(&loc, branch);
 	if (repo) {
 		if (remote)
 			*remote = loc;
diff --git a/core/qthelper.h b/core/qthelper.h
index 1fc2e55f3..cd28e1705 100644
--- a/core/qthelper.h
+++ b/core/qthelper.h
@@ -138,7 +138,7 @@ extern "C" {
 
 char *printGPSCoordsC(const location_t *loc);
 bool getProxyString(char **buffer);
-bool canReachCloudServer();
+bool canReachCloudServer(const char **remote);
 void updateWindowTitle();
 void subsurface_mkdir(const char *dir);
 char *get_file_name(const char *fileName);