[PATCH v2 pve-qemu-kvm] patches: pbs block driver: correct a data type

[Jing Luo]

gcc warns (-Werror=type-limits) that it will always be false for the
if statement. This is because here s->aid is defined as char, while
proxmox_restore_open_image() returns an int.

This is probably because chars are treated as unsigned on arm arch but
signed on x86 arch:

https://developer.arm.com/documentation/den0013/d/Porting/Miscellaneous-C-porting-issues/unsigned-char-and-signed-char

Signed-off-by: Jing Luo <jing at jing.rocks>
--
[changes since v1]
Use uint8_t for s->aid. Check the returned value from
proxmox_restore_open_image(), then assign it to s->aid.

Fiona: the doctor found no fish bone in my throat (probably swallowed),
so here's my best try :) I did minimal testing (it built).

I also found that chars are unsigned on riscv64, powerpc64le...not that
proxomx needs to worry about those arch though.
---
 ...ock-driver-to-map-backup-archives-into.patch | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/debian/patches/pve/0032-PVE-Add-PBS-block-driver-to-map-backup-archives-into.patch b/debian/patches/pve/0032-PVE-Add-PBS-block-driver-to-map-backup-archives-into.patch
index b9578ba..4c155c8 100644
--- a/debian/patches/pve/0032-PVE-Add-PBS-block-driver-to-map-backup-archives-into.patch
+++ b/debian/patches/pve/0032-PVE-Add-PBS-block-driver-to-map-backup-archives-into.patch
@@ -15,11 +15,11 @@ Signed-off-by: Wolfgang Bumiller <w.bumiller at proxmox.com>
 Signed-off-by: Fiona Ebner <f.ebner at proxmox.com>
 ---
  block/meson.build    |   2 +
- block/pbs.c          | 307 +++++++++++++++++++++++++++++++++++++++++++
+ block/pbs.c          | 310 +++++++++++++++++++++++++++++++++++++++++++
  meson.build          |   2 +-
  qapi/block-core.json |  29 ++++
  qapi/pragma.json     |   1 +
- 5 files changed, 340 insertions(+), 1 deletion(-)
+ 5 files changed, 343 insertions(+), 1 deletion(-)
  create mode 100644 block/pbs.c
 
 diff --git a/block/meson.build b/block/meson.build
@@ -37,10 +37,10 @@ index 6bba803f94..1945e04eeb 100644
  system_ss.add(files('block-ram-registrar.c'))
 diff --git a/block/pbs.c b/block/pbs.c
 new file mode 100644
-index 0000000000..dd72356bd3
+index 0000000000..9112d4dfe6
 --- /dev/null
 +++ b/block/pbs.c
-@@ -0,0 +1,307 @@
+@@ -0,0 +1,310 @@
 +/*
 + * Proxmox Backup Server read-only block driver
 + */
@@ -68,7 +68,7 @@ index 0000000000..dd72356bd3
 +
 +typedef struct {
 +    ProxmoxRestoreHandle *conn;
-+    char aid;
++    uint8_t aid;
 +    int64_t length;
 +
 +    char *repository;
@@ -201,12 +201,15 @@ index 0000000000..dd72356bd3
 +    }
 +
 +    /* acquire handle and length */
-+    s->aid = proxmox_restore_open_image(s->conn, s->archive, &pbs_error);
-+    if (s->aid < 0) {
++    ret = proxmox_restore_open_image(s->conn, s->archive, &pbs_error);
++    if (ret < 0 || ret > UINT8_MAX) {
 +        if (pbs_error && errp) error_setg(errp, "PBS open_image failed: %s", pbs_error);
 +        if (pbs_error) proxmox_backup_free_error(pbs_error);
 +        return -ENODEV;
++    } else {
++        s->aid = ret;
 +    }
++
 +    s->length = proxmox_restore_get_image_length(s->conn, s->aid, &pbs_error);
 +    if (s->length < 0) {
 +        if (pbs_error && errp) error_setg(errp, "PBS get_image_length failed: %s", pbs_error);
-- 
2.45.2