Mapping existing special mailbox fails after alreadyExists response (fixes #17)

Cargo.lock

@@ -91,9 +91,9 @@ dependencies = [
 
 [[package]]
 name = "anyhow"
-version = "1.0.102"
+version = "1.0.103"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7f202df86484c868dbad7eaa557ef785d5c66295e41b460ef922eca0723b842c"
+checksum = "2a4385e2e34eb35d6b3efe798b9eb88096925d87726c0798709bf56d9ed84af3"
 
 [[package]]
 name = "arrayref"
@@ -103,9 +103,9 @@ checksum = "76a2e8124351fda1ef8aaaa3bbd7ebbcb486bbcd4225aca0aa0d84bb2db8fecb"
 
 [[package]]
 name = "arrayvec"
-version = "0.7.7"
+version = "0.7.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f02882884d3e1bc524fb12c79f107f6ad0e1cfd498c536ffb494301740995dfe"
+checksum = "d3fb67a6e08acf24fdeccbac2cb6ac4305825bd1f117462e0e6f2f193345ad56"
 
 [[package]]
 name = "assert-json-diff"
@@ -119,15 +119,15 @@ dependencies = [
 
 [[package]]
 name = "astral-tokio-tar"
-version = "0.6.2"
+version = "0.6.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cb50a7aae84a03bf55b067832bc376f4961b790c97e64d3eacee97d389b90277"
+checksum = "08648fef353ab39a9d26f909ad53fc4f071be4c91853b78523f5cc3d9e5ebffd"
 dependencies = [
- "filetime",
  "futures-core",
  "libc",
  "portable-atomic",
  "rustc-hash",
+ "rustix 0.38.44",
  "tokio",
  "tokio-stream",
  "xattr",
@@ -180,9 +180,9 @@ checksum = "f2032f911046de80f0a198e0901378627c33f59ea0ac00e363d481118bd70a53"
 
 [[package]]
 name = "aws-lc-rs"
-version = "1.17.0"
+version = "1.17.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5ec2f1fc3ec205783a5da9a7e6c1509cc69dedf09a1949e412c1e18469326d00"
+checksum = "4342d8937fc7e5dd9b1c60292261c0670c882a2cd1719cfc11b1af41731e32ad"
 dependencies = [
  "aws-lc-sys",
  "zeroize",
@@ -190,14 +190,15 @@ dependencies = [
 
 [[package]]
 name = "aws-lc-sys"
-version = "0.41.0"
+version = "0.42.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1a2f9779ce85b93ab6170dd940ad0169b5766ff848247aff13bb788b832fe3f4"
+checksum = "6d9ceb1da931507a12f4fccea479dccd00da1943e1b4ae72d8e502d707361444"
 dependencies = [
  "cc",
  "cmake",
  "dunce",
  "fs_extra",
+ "pkg-config",
 ]
 
 [[package]]
@@ -384,9 +385,9 @@ dependencies = [
 
 [[package]]
 name = "cc"
-version = "1.2.65"
+version = "1.2.66"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e228eec9be7c17ccb640b59b36a5cd805ea2a564a4c5e162c2f659fea30d3b96"
+checksum = "f5d6cac793997bd970000024b2934968efe83b382de4fdcf4fcb46b6ee4ad996"
 dependencies = [
  "find-msvc-tools",
  "jobserver",
@@ -408,9 +409,9 @@ checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
 
 [[package]]
 name = "chacha20"
-version = "0.10.0"
+version = "0.10.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6f8d983286843e49675a4b7a2d174efe136dc93a18d69130dd18198a6c167601"
+checksum = "d524456ba66e72eb8b115ff89e01e497f8e6d11d78b70b1aa13c0fbd97540a81"
 dependencies = [
  "cfg-if",
  "cpufeatures",
@@ -586,18 +587,18 @@ dependencies = [
 
 [[package]]
 name = "crossbeam-channel"
-version = "0.5.15"
+version = "0.5.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "82b8f8f868b36967f9606790d1903570de9ceaf870a7bf9fbbd3016d636a2cb2"
+checksum = "d85363c37faeca707aef026efa9f3b34d077bce547e48f770770625c6013679e"
 dependencies = [
  "crossbeam-utils",
 ]
 
 [[package]]
 name = "crossbeam-utils"
-version = "0.8.21"
+version = "0.8.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d0a5c400df2834b80a4c3327b3aad3a4c4cd4de0629063962b03235697506a28"
+checksum = "61803da095bee82a81bb1a452ecc25d3b2f1416d1897eb86430c6159ef717c17"
 
 [[package]]
 name = "darling"
@@ -742,20 +743,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ee93edf3c501f0035bbeffeccfed0b79e14c311f12195ec0e661e114a0f60da4"
 dependencies = [
  "portable-atomic",
- "rand 0.10.1",
+ "rand 0.10.2",
  "web-time",
 ]
 
-[[package]]
-name = "filetime"
-version = "0.2.29"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5c287a33c7f0a620c38e641e7f60827713987b3c0f26e8ddc9462cc69cf75759"
-dependencies = [
- "cfg-if",
- "libc",
-]
-
 [[package]]
 name = "find-msvc-tools"
 version = "0.1.9"
@@ -979,9 +970,9 @@ dependencies = [
 
 [[package]]
 name = "hashlink"
-version = "0.12.0"
+version = "0.12.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a5081f264ed7adee96ea4b4778b6bb9da0a7228b084587aa3bd3ff05da7c5a3b"
+checksum = "32069d97bb81e38fa67eab65e3393bf804bb85969f2bc06bf13f64aef5aba248"
 dependencies = [
  "hashbrown 0.17.1",
 ]
@@ -1422,19 +1413,19 @@ dependencies = [
 
 [[package]]
 name = "jobserver"
-version = "0.1.34"
+version = "0.1.35"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9afb3de4395d6b3e67a780b6de64b51c978ecf11cb9a462c66be7d4ca9039d33"
+checksum = "1c00acbd29eabad4a2392fa0e921c874934dbbf4194312ad20f04a0ed67a3cb3"
 dependencies = [
- "getrandom 0.3.4",
+ "getrandom 0.4.3",
  "libc",
 ]
 
 [[package]]
 name = "js-sys"
-version = "0.3.102"
+version = "0.3.103"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "03d04c30968dffe80775bd4d7fb676131cd04a1fb46d2686dbffbaec2d9dfd31"
+checksum = "53b44bfcdb3f8d5837a46dae1ca9660a837176eee74a28b229bc626816589102"
 dependencies = [
  "cfg-if",
  "futures-util",
@@ -1458,6 +1449,12 @@ dependencies = [
  "vcpkg",
 ]
 
+[[package]]
+name = "linux-raw-sys"
+version = "0.4.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d26c52dbd32dccf2d10cac7725f8eae5296885fb5703b261f7d0a0739ec807ab"
+
 [[package]]
 name = "linux-raw-sys"
 version = "0.12.1"
@@ -1586,9 +1583,9 @@ dependencies = [
 
 [[package]]
 name = "num-bigint"
-version = "0.4.6"
+version = "0.4.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a5e44f723f1133c9deac646763579fdb3ac745e418f2a7af9cd0c431da1f20b9"
+checksum = "c89e69e7e0f03bea5ef08013795c25018e101932225a656383bd384495ecc367"
 dependencies = [
  "num-integer",
  "num-traits",
@@ -1854,9 +1851,9 @@ dependencies = [
 
 [[package]]
 name = "quick-xml"
-version = "0.40.1"
+version = "0.41.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2474bd2e5029e7ccb6abb2ba48cf2383a333851dedf495901544281590c7da7f"
+checksum = "e660451e55124f798a69a5af3f49ccfbefbd41910eefd25caf2393e1f3473ec1"
 dependencies = [
  "memchr",
 ]
@@ -1894,9 +1891,9 @@ dependencies = [
 
 [[package]]
 name = "rand"
-version = "0.10.1"
+version = "0.10.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d2e8e8bcc7961af1fdac401278c6a831614941f6164ee3bf4ce61b7edb162207"
+checksum = "c7f5fa3a058cd35567ef9bfa5e75732bee0f9e4c55fa90477bef2dfcdbc4be80"
 dependencies = [
  "chacha20",
  "getrandom 0.4.3",
@@ -2027,9 +2024,9 @@ dependencies = [
 
 [[package]]
 name = "rustc-hash"
-version = "2.1.2"
+version = "2.1.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "94300abf3f1ae2e2b8ffb7b58043de3d399c73fa6f4b73826402a5c457614dbe"
+checksum = "6b1e7f9a428571be2dc5bc0505c13fb6bf936822b894ec87abf8a08a4e51742d"
 
 [[package]]
 name = "rustc_version"
@@ -2040,6 +2037,19 @@ dependencies = [
  "semver",
 ]
 
+[[package]]
+name = "rustix"
+version = "0.38.44"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fdb5bc1ae2baa591800df16c9ca78619bf65c0488b41b96ccec5d11220d8c154"
+dependencies = [
+ "bitflags",
+ "errno",
+ "libc",
+ "linux-raw-sys 0.4.15",
+ "windows-sys 0.59.0",
+]
+
 [[package]]
 name = "rustix"
 version = "1.1.4"
@@ -2049,7 +2059,7 @@ dependencies = [
  "bitflags",
  "errno",
  "libc",
- "linux-raw-sys",
+ "linux-raw-sys 0.12.1",
  "windows-sys 0.61.2",
 ]
 
@@ -2083,9 +2093,9 @@ dependencies = [
 
 [[package]]
 name = "rustls-pki-types"
-version = "1.14.1"
+version = "1.15.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "30a7197ae7eb376e574fe940d068c30fe0462554a3ddbe4eca7838e049c937a9"
+checksum = "764899a24af3980067ee14bc143654f297b22eaebfe3c7b6b211920a5a59b046"
 dependencies = [
  "zeroize",
 ]
@@ -2152,9 +2162,9 @@ dependencies = [
 
 [[package]]
 name = "rustversion"
-version = "1.0.22"
+version = "1.0.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b39cdef0fa800fc44525c84ccb54a029961a8215f9619753635a9c0d2538d46d"
+checksum = "cf54715a573b99ac80df0bc206da022bcd442c974952c7b9720069370852e21f"
 
 [[package]]
 name = "ryu"
@@ -2505,7 +2515,7 @@ dependencies = [
  "fastrand",
  "getrandom 0.4.3",
  "once_cell",
- "rustix",
+ "rustix 1.1.4",
  "windows-sys 0.61.2",
 ]
 
@@ -2582,9 +2592,9 @@ dependencies = [
 
 [[package]]
 name = "time"
-version = "0.3.51"
+version = "0.3.53"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "85c17d80feb7334b40c484e45ed1a5273dfd8bfda537c3be2e74a06a6686f327"
+checksum = "18dfaaeddcb932337b5e7866ee7d0ce9b76d2fd092997146f187ec09b4558a50"
 dependencies = [
  "deranged",
  "num-conv",
@@ -2602,9 +2612,9 @@ checksum = "9e1c906769ad99c88eaa54e728060edef082f8e358ff32030cb7c7d315e81109"
 
 [[package]]
 name = "time-macros"
-version = "0.2.30"
+version = "0.2.31"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dcef1a61bdb119096e153208ec5cbec23944ce8bca13be5c7f60c634f7403935"
+checksum = "c431b87111666e491a90baa837f914fb45cd5dc3c268591b0220ff5057f2085f"
 dependencies = [
  "num-conv",
  "time-core",
@@ -2883,9 +2893,9 @@ checksum = "06abde3611657adf66d383f00b093d7faecc7fa57071cce2578660c9f1010821"
 
 [[package]]
 name = "uuid"
-version = "1.23.3"
+version = "1.23.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "144d6b123cef80b301b8f72a9e2ca4370ddec21950d0a103dd22c437006d2db7"
+checksum = "bf80a72845275afea99e7f2b434723d3bc7e38470fcd1c7ed39a599c73319a53"
 dependencies = [
  "sha1_smol",
 ]
@@ -2969,9 +2979,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen"
-version = "0.2.125"
+version = "0.2.126"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8ddb3f79143bced6de84270411622a2699cee572fc0875aeaf1e7867cf9fca1a"
+checksum = "4b067c0c11094aef6b7a801c1e34a26affafdf3d051dba08456b868789aaf9a4"
 dependencies = [
  "cfg-if",
  "once_cell",
@@ -2982,9 +2992,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro"
-version = "0.2.125"
+version = "0.2.126"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4e21a184b13fb19e157296e2c46056aec9092264fab83e4ba59e68c61b323c3d"
+checksum = "167ce5e579f6bcf889c4f7175a8a5a585de84e8ff93976ce393efa5f2837aab1"
 dependencies = [
  "quote",
  "wasm-bindgen-macro-support",
@@ -2992,9 +3002,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro-support"
-version = "0.2.125"
+version = "0.2.126"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fecefd9c35bd935a20fc3fc344b5f29138961e4f47fb03297d88f2587afb5ebd"
+checksum = "f3997c7839262f4ef12cf90b818d6340c18e80f263f1a94bf157d0ec4420380e"
 dependencies = [
  "bumpalo",
  "proc-macro2",
@@ -3005,9 +3015,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-shared"
-version = "0.2.125"
+version = "0.2.126"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "23939e44bb9a5d7576fa2b563dc2e136628f1224e88a8deed09e04858b77871f"
+checksum = "dc1b4cb0cc549fcf58d7dfc081778139b3d283a081644e833e84682ad71cea24"
 dependencies = [
  "unicode-ident",
 ]
@@ -3148,6 +3158,15 @@ dependencies = [
  "windows-targets 0.52.6",
 ]
 
+[[package]]
+name = "windows-sys"
+version = "0.59.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e38bc4d79ed67fd075bcc251a1c39b32a1776bbe92e5bef1f0bf1f8c531853b"
+dependencies = [
+ "windows-targets 0.52.6",
+]
+
 [[package]]
 name = "windows-sys"
 version = "0.61.2"
@@ -3297,7 +3316,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "32e45ad4206f6d2479085147f02bc2ef834ac85886624a23575ae137c8aa8156"
 dependencies = [
  "libc",
- "rustix",
+ "rustix 1.1.4",
 ]
 
 [[package]]
@@ -3325,18 +3344,18 @@ dependencies = [
 
 [[package]]
 name = "zerocopy"
-version = "0.8.52"
+version = "0.8.53"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ce1022995ff5ff5d841ad7d994facc23098cd40152f2c1d11cd607c6f530653f"
+checksum = "75726053136156d419e285b9b7eddaaea9e3fea6ce32eed44a89901f0bd98de1"
 dependencies = [
  "zerocopy-derive",
 ]
 
 [[package]]
 name = "zerocopy-derive"
-version = "0.8.52"
+version = "0.8.53"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1ae7f38b72ec2a254e2b87ef277cf2cd4fb97cbebf944faa6f33354da0867930"
+checksum = "4714fd92cf900833d49538023a9b3915155210801d1c1169eba513b2addefd71"
 dependencies = [
  "proc-macro2",
  "quote",

Cargo.toml

@@ -39,7 +39,7 @@ rustls = { version = "0.23.40", default-features = false, features = ["aws-lc-rs
 rustls-platform-verifier = "0.7"
 regex  = "1.12"
 flate2 = "1.1.9"
-quick-xml = "0.40"
+quick-xml = "0.41"
 chrono = { version = "0.4", default-features = false, features = ["std"] }
 chrono-tz = { version = "0.10", default-features = false }
 

src/sync/export/tree.rs

@@ -93,6 +93,44 @@ fn depth(local: i64, by: &HashMap<i64, Option<i64>>) -> usize {
     d
 }
 
+fn already_exists_id(err: &Value) -> Option<String> {
+    if err.get("type").and_then(Value::as_str) == Some("alreadyExists") {
+        err.get("existingId")
+            .and_then(Value::as_str)
+            .map(str::to_owned)
+    } else {
+        None
+    }
+}
+
+fn find_name_collision(
+    targets: &[TargetNode],
+    parent_target: Option<&str>,
+    name: &str,
+) -> Option<String> {
+    targets
+        .iter()
+        .find(|t| t.parent.as_deref() == parent_target && fold_name(&t.name) == fold_name(name))
+        .map(|t| t.id.clone())
+}
+
+fn record_merge(
+    ty: ObjectType,
+    local: i64,
+    target_id: String,
+    reason: &str,
+    maps: &mut Maps,
+    tmatched: &mut HashSet<String>,
+    logger: &Logger,
+) {
+    logger.warn(&format!(
+        "{} local {local} merged into existing target {target_id}: {reason}",
+        ty.jmap_name()
+    ));
+    maps.insert(ty, local, JmapId(target_id.clone()));
+    tmatched.insert(target_id);
+}
+
 pub fn reconcile(
     ctx: &Context,
     net: &Net,
@@ -170,9 +208,11 @@ pub fn reconcile(
             .collect();
         if interleave {
             for n in &level {
-                if let Some(p) = n.parent
+                let parent_target = match n.parent {
-                    && maps.target(ty, p).is_none()
+                    None => None,
-                {
+                    Some(p) => match maps.target(ty, p) {
+                        Some(t) => Some(t.0),
+                        None => {
                             logger.warn(&format!(
                                 "{} local {} skipped: parent {} not created",
                                 ty.jmap_name(),
@@ -182,6 +222,21 @@ pub fn reconcile(
                             counts.failed += 1;
                             continue;
                         }
+                    },
+                };
+                if let Some(tid) = find_name_collision(&targets, parent_target.as_deref(), &n.name) {
+                    record_merge(
+                        ty,
+                        n.local,
+                        tid,
+                        "name already present on target",
+                        maps,
+                        &mut tmatched,
+                        logger,
+                    );
+                    counts.skipped += 1;
+                    continue;
+                }
                 let cid = format!("c{}", n.local);
                 let _ = uploader.take_touched();
                 let obj = match build_create(ctx, ty, n.local, maps, &mut uploader) {
@@ -228,6 +283,20 @@ pub fn reconcile(
                     }
                 }
                 for (cid, err) in &outcome.not_created {
+                    let local = cid.strip_prefix('c').and_then(|s| s.parse::<i64>().ok());
+                    if let (Some(local), Some(existing)) = (local, already_exists_id(err)) {
+                        record_merge(
+                            ty,
+                            local,
+                            existing,
+                            "alreadyExists: reusing existing target",
+                            maps,
+                            &mut tmatched,
+                            logger,
+                        );
+                        counts.skipped += 1;
+                        continue;
+                    }
                     logger.warn(&format!("{} {cid} not created: {err}", ty.jmap_name()));
                     counts.failed += 1;
                 }
@@ -236,9 +305,11 @@ pub fn reconcile(
         }
         let mut batch: Vec<(String, Value)> = Vec::new();
         for n in &level {
-            if let Some(p) = n.parent
+            let parent_target = match n.parent {
-                && maps.target(ty, p).is_none()
+                None => None,
-            {
+                Some(p) => match maps.target(ty, p) {
+                    Some(t) => Some(t.0),
+                    None => {
                         logger.warn(&format!(
                             "{} local {} skipped: parent {} not created",
                             ty.jmap_name(),
@@ -248,6 +319,21 @@ pub fn reconcile(
                         counts.failed += 1;
                         continue;
                     }
+                },
+            };
+            if let Some(tid) = find_name_collision(&targets, parent_target.as_deref(), &n.name) {
+                record_merge(
+                    ty,
+                    n.local,
+                    tid,
+                    "name already present on target",
+                    maps,
+                    &mut tmatched,
+                    logger,
+                );
+                counts.skipped += 1;
+                continue;
+            }
             match build_create(ctx, ty, n.local, maps, &mut uploader) {
                 Ok(mut obj) => {
                     if ty == ObjectType::Mailbox
@@ -290,6 +376,20 @@ pub fn reconcile(
             }
         }
         for (cid, err) in &outcome.not_created {
+            let local = cid.strip_prefix('c').and_then(|s| s.parse::<i64>().ok());
+            if let (Some(local), Some(existing)) = (local, already_exists_id(err)) {
+                record_merge(
+                    ty,
+                    local,
+                    existing,
+                    "alreadyExists: reusing existing target",
+                    maps,
+                    &mut tmatched,
+                    logger,
+                );
+                counts.skipped += 1;
+                continue;
+            }
             logger.warn(&format!("{} {cid} not created: {err}", ty.jmap_name()));
             counts.failed += 1;
         }

tests/mock_sync.rs

@@ -173,6 +173,319 @@ fn export_email_already_exists_is_matched_not_failed() {
     let _ = std::fs::remove_file(&archive);
 }
 
+#[test]
+fn export_mailbox_name_collision_merges_without_create() {
+    let mut server = mockito::Server::new();
+    let base = server.url();
+    let api = "/jmap/api";
+
+    let archive = tmp();
+    {
+        let conn = db::init::open(&archive).unwrap();
+        conn.execute(
+            "INSERT INTO mailboxes (id,name,parent_id,role) VALUES
+                 (1,'Junk Email',NULL,'junk'),
+                 (2,'Junk Mail',NULL,NULL)",
+            [],
+        )
+        .unwrap();
+        let blob = db::blobs::intern_blob(
+            &conn,
+            b"From: a@x\r\nSubject: spam\r\nMessage-ID: <m-2@h>\r\n\r\nbody",
+        )
+        .unwrap();
+        conn.execute(
+            "INSERT INTO emails (blob_id,received_at,mailbox_ids,keywords)
+             VALUES (?1,'2020-01-01T00:00:00Z','[2]','[\"$seen\"]')",
+            rusqlite::params![blob],
+        )
+        .unwrap();
+    }
+
+    let _root = server.mock("GET", "/").with_status(404).create();
+    let _wk = server
+        .mock("GET", "/.well-known/jmap")
+        .with_body(session_body(&base))
+        .create();
+
+    let _mq1 = server
+        .mock("POST", api)
+        .match_body(Matcher::Regex("Mailbox/query".into()))
+        .with_body(
+            json!({"methodResponses":[["Mailbox/query",
+            {"accountId":"w","ids":["c"]},"q"]]})
+            .to_string(),
+        )
+        .expect(1)
+        .create();
+    let _mq2 = server
+        .mock("POST", api)
+        .match_body(Matcher::Regex("Mailbox/query".into()))
+        .with_body(
+            json!({"methodResponses":[["Mailbox/query",
+            {"accountId":"w","ids":[]},"q"]]})
+            .to_string(),
+        )
+        .expect(1)
+        .create();
+    let _mg = server
+        .mock("POST", api)
+        .match_body(Matcher::Regex("Mailbox/get".into()))
+        .with_body(
+            json!({"methodResponses":[["Mailbox/get",{"accountId":"w","list":[
+            {"id":"c","name":"Junk Mail","role":"junk","parentId":null,
+             "myRights":{"mayDelete":true}}],"notFound":[]},"g"]]})
+            .to_string(),
+        )
+        .expect(1)
+        .create();
+
+    let no_set = server
+        .mock("POST", api)
+        .match_body(Matcher::Regex("Mailbox/set".into()))
+        .expect(0)
+        .create();
+
+    let _eq = server
+        .mock("POST", api)
+        .match_body(Matcher::Regex("Email/query".into()))
+        .with_body(
+            json!({"methodResponses":[["Email/query",
+            {"accountId":"w","ids":[]},"q"]]})
+            .to_string(),
+        )
+        .expect(1)
+        .create();
+    let _up = server
+        .mock("POST", Matcher::Regex("/jmap/upload/".into()))
+        .with_body(json!({"blobId":"UPLOADED"}).to_string())
+        .expect(1)
+        .create();
+    let import_into_c = server
+        .mock("POST", api)
+        .match_body(Matcher::AllOf(vec![
+            Matcher::Regex("Email/import".into()),
+            Matcher::Regex(r#""c":true"#.into()),
+        ]))
+        .with_body(
+            json!({"methodResponses":[["Email/import",{"accountId":"w",
+                "created":{"e1":{"id":"E1","blobId":"b","threadId":"t","size":10}}},"i"]]})
+            .to_string(),
+        )
+        .expect(1)
+        .create();
+
+    let summary = sync::export::run(
+        CommonConfig {
+            archive: archive.clone(),
+            threads: 1,
+            dry_run: false,
+            max_retries: 1,
+            allow_invalid_certs: false,
+            logger: Logger::from_flags(true, 0),
+        },
+        ExportConfig {
+            connect: ConnectConfig {
+                url: base.clone(),
+                auth: Auth::Basic {
+                    user: "u".into(),
+                    password: "p".into(),
+                },
+                account: AccountSelector::Id("w".into()),
+            },
+            objects: None,
+            prune: false,
+            yes: true,
+        },
+    )
+    .expect("export run");
+
+    let mailbox = summary
+        .per_type
+        .iter()
+        .find(|(t, _)| *t == "Mailbox")
+        .map(|(_, c)| c.clone())
+        .expect("mailbox counts");
+    assert_eq!(mailbox.created, 0, "no mailbox is created");
+    assert_eq!(mailbox.failed, 0, "the name collision is not a failure");
+    assert_eq!(
+        mailbox.skipped, 2,
+        "role-matched Junk Email + merged Junk Mail"
+    );
+
+    let email = summary
+        .per_type
+        .iter()
+        .find(|(t, _)| *t == "Email")
+        .map(|(_, c)| c.clone())
+        .expect("email counts");
+    assert_eq!(email.created, 1, "the Junk Mail email lands on the target");
+    assert_eq!(email.failed, 0);
+    assert!(!summary.any_failed());
+
+    no_set.assert();
+    import_into_c.assert();
+    let _ = std::fs::remove_file(&archive);
+}
+
+#[test]
+fn export_mailbox_already_exists_maps_existing_id() {
+    let mut server = mockito::Server::new();
+    let base = server.url();
+    let api = "/jmap/api";
+
+    let archive = tmp();
+    {
+        let conn = db::init::open(&archive).unwrap();
+        conn.execute(
+            "INSERT INTO mailboxes (id,name,parent_id,role) VALUES (1,'Junk Mail',NULL,NULL)",
+            [],
+        )
+        .unwrap();
+        let blob = db::blobs::intern_blob(
+            &conn,
+            b"From: a@x\r\nSubject: spam\r\nMessage-ID: <m-3@h>\r\n\r\nbody",
+        )
+        .unwrap();
+        conn.execute(
+            "INSERT INTO emails (blob_id,received_at,mailbox_ids,keywords)
+             VALUES (?1,'2020-01-01T00:00:00Z','[1]','[\"$seen\"]')",
+            rusqlite::params![blob],
+        )
+        .unwrap();
+    }
+
+    let _root = server.mock("GET", "/").with_status(404).create();
+    let _wk = server
+        .mock("GET", "/.well-known/jmap")
+        .with_body(session_body(&base))
+        .create();
+
+    let _mq1 = server
+        .mock("POST", api)
+        .match_body(Matcher::Regex("Mailbox/query".into()))
+        .with_body(
+            json!({"methodResponses":[["Mailbox/query",
+            {"accountId":"w","ids":["t1"]},"q"]]})
+            .to_string(),
+        )
+        .expect(1)
+        .create();
+    let _mq2 = server
+        .mock("POST", api)
+        .match_body(Matcher::Regex("Mailbox/query".into()))
+        .with_body(
+            json!({"methodResponses":[["Mailbox/query",
+            {"accountId":"w","ids":[]},"q"]]})
+            .to_string(),
+        )
+        .expect(1)
+        .create();
+    let _mg = server
+        .mock("POST", api)
+        .match_body(Matcher::Regex("Mailbox/get".into()))
+        .with_body(
+            json!({"methodResponses":[["Mailbox/get",{"accountId":"w","list":[
+            {"id":"t1","name":"Inbox","role":"inbox","parentId":null,
+             "myRights":{"mayDelete":true}}],"notFound":[]},"g"]]})
+            .to_string(),
+        )
+        .expect(1)
+        .create();
+
+    let set_collides = server
+        .mock("POST", api)
+        .match_body(Matcher::Regex("Mailbox/set".into()))
+        .with_body(
+            json!({"methodResponses":[["Mailbox/set",{"accountId":"w",
+                "notCreated":{"c1":{"type":"alreadyExists","existingId":"c"}}},"s"]]})
+            .to_string(),
+        )
+        .expect(1)
+        .create();
+
+    let _eq = server
+        .mock("POST", api)
+        .match_body(Matcher::Regex("Email/query".into()))
+        .with_body(
+            json!({"methodResponses":[["Email/query",
+            {"accountId":"w","ids":[]},"q"]]})
+            .to_string(),
+        )
+        .expect(1)
+        .create();
+    let _up = server
+        .mock("POST", Matcher::Regex("/jmap/upload/".into()))
+        .with_body(json!({"blobId":"UPLOADED"}).to_string())
+        .expect(1)
+        .create();
+    let import_into_c = server
+        .mock("POST", api)
+        .match_body(Matcher::AllOf(vec![
+            Matcher::Regex("Email/import".into()),
+            Matcher::Regex(r#""c":true"#.into()),
+        ]))
+        .with_body(
+            json!({"methodResponses":[["Email/import",{"accountId":"w",
+                "created":{"e1":{"id":"E1","blobId":"b","threadId":"t","size":10}}},"i"]]})
+            .to_string(),
+        )
+        .expect(1)
+        .create();
+
+    let summary = sync::export::run(
+        CommonConfig {
+            archive: archive.clone(),
+            threads: 1,
+            dry_run: false,
+            max_retries: 1,
+            allow_invalid_certs: false,
+            logger: Logger::from_flags(true, 0),
+        },
+        ExportConfig {
+            connect: ConnectConfig {
+                url: base.clone(),
+                auth: Auth::Basic {
+                    user: "u".into(),
+                    password: "p".into(),
+                },
+                account: AccountSelector::Id("w".into()),
+            },
+            objects: None,
+            prune: false,
+            yes: true,
+        },
+    )
+    .expect("export run");
+
+    let mailbox = summary
+        .per_type
+        .iter()
+        .find(|(t, _)| *t == "Mailbox")
+        .map(|(_, c)| c.clone())
+        .expect("mailbox counts");
+    assert_eq!(mailbox.created, 0, "the create collided");
+    assert_eq!(
+        mailbox.failed, 0,
+        "alreadyExists on Mailbox/set is not a failure"
+    );
+    assert_eq!(mailbox.skipped, 1, "existingId folds into matched");
+
+    let email = summary
+        .per_type
+        .iter()
+        .find(|(t, _)| *t == "Email")
+        .map(|(_, c)| c.clone())
+        .expect("email counts");
+    assert_eq!(email.created, 1, "the email lands in the existing folder");
+    assert_eq!(email.failed, 0);
+    assert!(!summary.any_failed());
+
+    set_collides.assert();
+    import_into_c.assert();
+    let _ = std::fs::remove_file(&archive);
+}
+
 #[test]
 fn email_export_sends_one_email_per_import_call() {
     let mut server = mockito::Server::new();