Better handling of special cases (#450)

Author: Byron

git-refspec/src/parse.rs

@@ -29,7 +29,17 @@ pub(crate) mod function {
                 Mode::Force
             }
             Some(_) => Mode::Normal,
-            None => return Err(Error::Empty),
+            None => {
+                return match operation {
+                    Operation::Push => Err(Error::Empty),
+                    Operation::Fetch => Ok(RefSpecRef {
+                        mode: Mode::Normal,
+                        op: operation,
+                        src: Some("HEAD".into()),
+                        dst: None,
+                    }),
+                }
+            }
         };
 
         let (src, dst) = match spec.find_byte(b':') {
@@ -43,7 +53,10 @@ pub(crate) mod function {
                 let src = (!src.is_empty()).then(|| src.as_bstr());
                 let dst = (!dst.is_empty()).then(|| dst.as_bstr());
                 match (src, dst) {
-                    (None, None) => (None, None),
+                    (None, None) => match operation {
+                        Operation::Push => (None, None),
+                        Operation::Fetch => (Some("HEAD".into()), None),
+                    },
                     (None, Some(dst)) => match operation {
                         Operation::Push => (None, Some(dst)),
                         Operation::Fetch => (Some("HEAD".into()), Some(dst)),

git-refspec/src/spec.rs

@@ -34,11 +34,6 @@ impl RefSpecRef<'_> {
             (Operation::Push, Mode::Normal | Mode::Force, None, None) => Instruction::Push(Push::AllMatchingBranches {
                 allow_non_fast_forward: matches!(self.mode, Mode::Force),
             }),
-            (Operation::Fetch, Mode::Normal | Mode::Force, None, None) => {
-                Instruction::Fetch(Fetch::AllMatchingBranches {
-                    allow_non_fast_forward: matches!(self.mode, Mode::Force),
-                })
-            }
             (Operation::Push, Mode::Normal | Mode::Force, Some(src), Some(dst)) if has_pattern(src) => {
                 Instruction::Push(Push::MultipleWithGlob {
                     src,

git-refspec/src/types.rs

@@ -70,11 +70,6 @@ pub enum Push<'a> {
 
 #[derive(PartialEq, Eq, Copy, Clone, Hash, Debug)]
 pub enum Fetch<'a> {
-    /// TODO: figure out what this actually does - it's valid for sure and only fetches HEAD -> FETCH_HEAD apparently
-    AllMatchingBranches {
-        /// Unclear what this does, but it's allowed
-        allow_non_fast_forward: bool,
-    },
     Only {
         /// The ref name to fetch on the remote side, without updating the local side.
         src: &'a BStr,

git-refspec/tests/fixtures/generated-archives/make_baseline.tar.xz

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:515045d1eade39e1aeee1f171216ac389b8adc54af541b2ff49bf1b1ab68eae2
-size 9340
+oid sha256:d68f02fcf17b72dfb953ab02f3d448d7b859d822aa71835856045a291a645d5a
+size 9344

git-refspec/tests/fixtures/make_baseline.sh

@@ -64,6 +64,7 @@ baseline push ':'
 
 baseline fetch ''
 baseline fetch ':'
+baseline fetch '+'
 baseline push 'refs/heads/main:refs/remotes/frotz/xyzzy'
 baseline push 'refs/heads/*:refs/remotes/frotz/*'
 

git-refspec/tests/parse/mod.rs

@@ -33,7 +33,7 @@ fn baseline() {
             Ok(res) => match (res.is_ok(), err_code == 0) {
                 (true, true) | (false, false) => {}
                 _ => {
-                    eprintln!("{res:?} {err_code} {} {:?}", kind.as_bstr(), spec.as_bstr());
+                    eprintln!("{err_code} {res:?} {} {:?}", kind.as_bstr(), spec.as_bstr());
                     mismatch += 1;
                 }
             },
@@ -59,7 +59,6 @@ mod invalid {
 
     #[test]
     fn empty() {
-        assert!(matches!(try_parse("", Operation::Fetch).unwrap_err(), Error::Empty));
         assert!(matches!(try_parse("", Operation::Push).unwrap_err(), Error::Empty));
     }
 
@@ -142,19 +141,15 @@ mod fetch {
     }
 
     #[test]
-    fn colon_alone_is_for_fetching_into_fetchhead() {
-        assert_parse(
-            ":",
-            Instruction::Fetch(Fetch::AllMatchingBranches {
-                allow_non_fast_forward: false,
-            }),
-        );
-        assert_parse(
-            "+:",
-            Instruction::Fetch(Fetch::AllMatchingBranches {
-                allow_non_fast_forward: true,
-            }),
-        );
+    fn colon_alone_is_for_fetching_head_into_fetchhead() {
+        assert_parse(":", Instruction::Fetch(Fetch::Only { src: b("HEAD") }));
+        let spec = assert_parse("+:", Instruction::Fetch(Fetch::Only { src: b("HEAD") }));
+        assert_eq!(spec.mode(), Mode::Force, "it's set even though it's not useful");
+    }
+
+    #[test]
+    fn empty_refspec_is_enough_for_fetching_head_into_fetchhead() {
+        assert_parse("", Instruction::Fetch(Fetch::Only { src: b("HEAD") }));
     }
 }