Fix resolution of a name that's a prefix of another name (#2521)

libexec/pyenv-latest

@@ -35,6 +35,12 @@ IFS=$'\n'
     else
         DEFINITION_CANDIDATES=( $(python-build --definitions ) )
     fi
+    
+    if printf '%s\n' "${DEFINITION_CANDIDATES[@]}" | grep -qxFe "$prefix"; then
+        echo "$prefix"
+        exit $exitcode;
+    fi
+    
     # https://stackoverflow.com/questions/11856054/is-there-an-easy-way-to-pass-a-raw-string-to-grep/63483807#63483807 
     prefix_re="$(sed 's/[^\^]/[&]/g;s/[\^]/\\&/g' <<< "$prefix")"
     # FIXME: more reliable and readable would probably be to loop over them and transform in pure Bash

test/latest.bats

@@ -64,6 +64,21 @@ pyenv: no known versions match the prefix \`3.8'
 !
 }
 
+@test "complete name resolves to itself" {
+  create_executable pyenv-versions <<!
+#!$BASH
+echo foo
+echo foo.bar
+!
+
+run pyenv-latest foo
+assert_success
+assert_output <<!
+foo
+!
+
+}
+
 @test "sort CPython" {
   create_executable pyenv-versions <<!
 #!$BASH