Fix #1122 - Handle notes for shellcheck errors again, and use type 'I' for notes

ale_linters/sh/shellcheck.vim

@@ -70,6 +70,41 @@ function! ale_linters#sh#shellcheck#GetCommand(buffer, version_output) abort
     \   . ' -f gcc -'
 endfunction
 
+function! ale_linters#sh#shellcheck#Handle(buffer, lines) abort
+    let l:pattern = '\v^([a-zA-Z]?:?[^:]+):(\d+):(\d+)?:? ([^:]+): (.+)$'
+    let l:output = []
+
+    for l:match in ale#util#GetMatches(a:lines, l:pattern)
+        if l:match[4] is# 'error'
+            let l:type = 'E'
+        elseif l:match[4] is# 'note'
+            let l:type = 'I'
+        else
+            let l:type = 'W'
+        endif
+
+        let l:item = {
+        \   'lnum': str2nr(l:match[2]),
+        \   'type': l:type,
+        \   'text': l:match[5],
+        \}
+
+        if !empty(l:match[3])
+            let l:item.col = str2nr(l:match[3])
+        endif
+
+        " If the filename is something like <stdin>, <nofile> or -, then
+        " this is an error for the file we checked.
+        if l:match[1] isnot# '-' && l:match[1][0] isnot# '<'
+            let l:item['filename'] = l:match[1]
+        endif
+
+        call add(l:output, l:item)
+    endfor
+
+    return l:output
+endfunction
+
 call ale#linter#Define('sh', {
 \   'name': 'shellcheck',
 \   'executable_callback': 'ale_linters#sh#shellcheck#GetExecutable',
@@ -77,5 +112,5 @@ call ale#linter#Define('sh', {
 \       {'callback': 'ale_linters#sh#shellcheck#VersionCheck'},
 \       {'callback': 'ale_linters#sh#shellcheck#GetCommand'},
 \   ],
-\   'callback': 'ale#handlers#gcc#HandleGCCFormat',
+\   'callback': 'ale_linters#sh#shellcheck#Handle',
 \})