51860: simplify suffix handling in _prefix to remove less accurate hack

This solves the following problems in the _prefix completer:
- The old code had logic for dealing with compstate[unambiguous] that
  was unnecessary. It works fine without it.
- Because of this logic, if a widget set compstate[insert]=1 after
  calling _main_complete, an `x` was left after the completion on the
  command line.
- If the same widget also set `compstate[to_end]=`, then instead, the
  last character of the inserted completion would be treated as an
  autoremovable suffix, with the actual suffix being inserted to the
  line as a normal character.
- After inserting a completion, the cursor would move to the end of the
  entire current word on the command, not the end of word that was
  inserted. This is not what you want with _prefix, since you are trying
  to complete a word _before_ the one on the command line, after which
  you usually want to insert a separator, such as a space or slash,
  before the next word.

1 files changed, 48 insertions, 0 deletions

diff --git a/Test/Y01completion.ztst b/Test/Y01completion.ztst
index fb369ea69..fc18b19a4 100644
--- a/Test/Y01completion.ztst
+++ b/Test/Y01completion.ztst
@@ -35,6 +35,54 @@
 >line: {: dir1/}{}
 >line: {: dir2/}{}
 
+  comptest $': d\t\t\t\t\t \t'
+0:unambiguous prefix and autoremovable suffix
+>line: {: dir}{}
+>line: {: dir}{}
+>DESCRIPTION:{file}
+>DI:{dir1}
+>DI:{dir2}
+>line: {: dir1/}{}
+>line: {: dir2/}{}
+>line: {: dir1/}{}
+>line: {: dir1 }{}
+>DESCRIPTION:{file}
+>DI:{dir1}
+>DI:{dir2}
+>FI:{file1}
+>FI:{file2}
+
+  comptest $': suf\ebd\t\t\t\t\t \t'
+0:unambiguous prefix and autoremovable suffix with _prefix completer
+>line: {: dir}{suf}
+>line: {: dir}{suf}
+>DESCRIPTION:{file}
+>DI:{dir1}
+>DI:{dir2}
+>line: {: dir1/}{suf}
+>line: {: dir2/}{suf}
+>line: {: dir1/}{suf}
+>line: {: dir1 }{suf}
+>DESCRIPTION:{file}
+>DI:{dir1}
+>DI:{dir2}
+>FI:{file1}
+>FI:{file2}
+F:regression test workers/51641
+
+  comptesteval 'comptest-postfunc() { compstate[insert]=1 compstate[list]= }'
+  comptest $': \t \t'
+0:compstate[insert]=1 compstate[list]=
+>line: {: dir1/}{}
+>line: {: dir1 dir1/}{}
+
+  comptest $': suf\eb\t \t'
+0:compstate[insert]=1 compstate[list]= with _prefix completer
+>line: {: dir1/}{suf}
+>line: {: dir1 dir1/}{suf}
+F:regression test workers/51641
+
+  comptesteval 'comptest-postfunc() {}'
   comptest $': *\t\t\t\t\t\t'
 0:_expand shows file types
 >line: {: dir1/}{}