Fix :squash() for histories containing an empty orphan (#1350)

The implementation relied on the orphan commit being dropped
by the normal drop rules, but those have an exception to keep
empty trees.

Change: squash-empty-orphan

Author: christian-schilling

josh-core/src/cache.rs

@@ -1,7 +1,7 @@
 use super::*;
 use std::collections::HashMap;
 
-const CACHE_VERSION: u64 = 20;
+const CACHE_VERSION: u64 = 21;
 
 lazy_static! {
     static ref DB: std::sync::Mutex<Option<sled::Db>> = std::sync::Mutex::new(None);

josh-core/src/filter/mod.rs

@@ -741,7 +741,12 @@ fn apply_to_commit2(
                         },
                     );
                 }
-                tree::empty(repo)
+                return Ok(Some(history::drop_commit(
+                    commit,
+                    vec![],
+                    transaction,
+                    filter,
+                )?));
             }
         }
         Op::Linear => {

tests/filter/squash.t

@@ -30,9 +30,6 @@
 
   $ josh-filter -s --squash-pattern "refs/tags/*" --update refs/heads/filtered
   Warning: reference refs/heads/filtered wasn't updated
-  [1] :squash(
-  
-  )
 
   $ git log --graph --decorate --pretty=oneline refs/heads/filtered
   fatal: ambiguous argument 'refs/heads/filtered': unknown revision or path not in the working tree.
@@ -45,9 +42,6 @@ This one tag is an annotated tag, to make sure those are handled as well
   $ josh-filter -s --squash-pattern "refs/tags/*" :author=\"New\ Author\"\;\"new@e.mail\" --update refs/heads/filtered
   [1] :author="New Author";"new@e.mail"
   [1] :squash(
-  
-  )
-  [2] :squash(
       1d69b7d2651f744be3416f2ad526aeccefb99310:"refs/tags/tag_a"
   )
 
@@ -67,9 +61,6 @@ This one tag is an annotated tag, to make sure those are handled as well
 
   $ josh-filter -s --squash-pattern "refs/tags/*" :author=\"New\ Author\"\;\"new@e.mail\" --update refs/heads/filtered
   [1] :squash(
-  
-  )
-  [2] :squash(
       1d69b7d2651f744be3416f2ad526aeccefb99310:"refs/tags/tag_a"
   )
   [3] :squash(
@@ -124,9 +115,6 @@ This one tag is an annotated tag, to make sure those are handled as well
   ):author="New Author";"new@e.mail"
   $ josh-filter -s --file filter.josh --update refs/heads/filtered
   [1] :squash(
-  
-  )
-  [2] :squash(
       1d69b7d2651f744be3416f2ad526aeccefb99310:"refs/tags/tag_a"
   )
   [3] :squash(

tests/filter/squash_empty_initial.t

@@ -0,0 +1,54 @@
+  $ export RUST_BACKTRACE=1
+  $ git init -q 1> /dev/null
+
+  $ git commit -m "Empty initial" --allow-empty 1> /dev/null
+
+  $ git log --graph --pretty=%s
+  * Empty initial
+
+  $ git checkout -b branch2
+  Switched to a new branch 'branch2'
+
+  $ echo contents2 > file1
+  $ git add .
+  $ git commit -m "mod file1" 1> /dev/null
+
+  $ echo contents3 > file3
+  $ git add .
+  $ git commit -m "mod file3" 1> /dev/null
+
+  $ git checkout master
+  Switched to branch 'master'
+
+  $ echo contents3 > file2
+  $ git add .
+  $ git commit -m "add file2" 1> /dev/null
+
+  $ git merge -q branch2 --no-ff
+
+  $ git log --graph --decorate --pretty=oneline
+  *   882f2656a5075936eb37bfefde740e0b453e4479 (HEAD -> master) Merge branch 'branch2'
+  |\  
+  | * 87bb87b63d1745136cb2ea167ef3ffc82c7ef3f0 (branch2) mod file3
+  | * 2db14eafe99deeeab5db07bf33e332d523a298ab mod file1
+  * | 54d8f704681c3b44a468cef655fa3b5bc5229a4c add file2
+  |/  
+  * 8c26fa0172bda17bafcbcf9684e639c6b0bae9c4 Empty initial
+
+  $ josh-filter -s --squash-pattern "refs/tags/*" --update refs/heads/filtered
+  Warning: reference refs/heads/filtered wasn't updated
+  $ git log --graph --decorate --pretty=oneline refs/heads/filtered
+  fatal: ambiguous argument 'refs/heads/filtered': unknown revision or path not in the working tree.
+  Use '--' to separate paths from revisions, like this:
+  'git <command> [<revision>...] -- [<file>...]'
+  [128]
+
+  $ git tag -a tag_a -m "created a tag" 882f2656a5075936eb37bfefde740e0b453e4479
+  $ josh-filter -s --squash-pattern "refs/tags/*" :author=\"New\ Author\"\;\"new@e.mail\" --update refs/heads/filtered
+  [1] :author="New Author";"new@e.mail"
+  [1] :squash(
+      882f2656a5075936eb37bfefde740e0b453e4479:"refs/tags/tag_a"
+  )
+
+  $ git log --graph --decorate --pretty=oneline refs/heads/filtered
+  * d8aa5a9937f4f0bd645dbc0b591bae5cd6b6d91b (tag: filtered/tag_a, filtered) refs/tags/tag_a

tests/proxy/amend_patchset.t

@@ -124,7 +124,7 @@
   ]
   .
   |-- josh
-  |   `-- 20
+  |   `-- 21
   |       `-- sled
   |           |-- blobs
   |           |-- conf

tests/proxy/authentication.t

@@ -124,7 +124,7 @@
   "real_repo.git" = ["::sub1/"]
   .
   |-- josh
-  |   `-- 20
+  |   `-- 21
   |       `-- sled
   |           |-- blobs
   |           |-- conf

tests/proxy/caching.t

@@ -51,7 +51,7 @@
   ]
   .
   |-- josh
-  |   `-- 20
+  |   `-- 21
   |       `-- sled
   |           |-- blobs
   |           |-- conf
@@ -162,7 +162,7 @@
   ]
   .
   |-- josh
-  |   `-- 20
+  |   `-- 21
   |       `-- sled
   |           |-- blobs
   |           |-- conf

tests/proxy/clone_absent_head.t

@@ -85,7 +85,7 @@
   $ bash ${TESTDIR}/destroy_test_env.sh
   .
   |-- josh
-  |   `-- 20
+  |   `-- 21
   |       `-- sled
   |           |-- blobs
   |           |-- conf

tests/proxy/clone_all.t

@@ -53,7 +53,7 @@
   "real_repo.git" = ["::sub1/"]
   .
   |-- josh
-  |   `-- 20
+  |   `-- 21
   |       `-- sled
   |           |-- blobs
   |           |-- conf

tests/proxy/clone_blocked.t

@@ -9,7 +9,7 @@
   $ bash ${TESTDIR}/destroy_test_env.sh
   .
   |-- josh
-  |   `-- 20
+  |   `-- 21
   |       `-- sled
   |           |-- blobs
   |           |-- conf