Fix issue #1688: from statements removed when invalid

2 files changed, 45 insertions, 30 deletions

diff --git a/isort/core.py b/isort/core.py
index 59878998..d763ad46 100644
--- a/isort/core.py
+++ b/isort/core.py
@@ -246,9 +246,6 @@ def process(
                 ):
                     import_section += line
                 elif stripped_line.startswith(IMPORT_START_IDENTIFIERS):
-                    did_contain_imports = contains_imports
-                    contains_imports = True
-
                     new_indent = line[: -len(line.lstrip())]
                     import_statement = line
                     stripped_line = line.strip().split("#")[0]
@@ -266,37 +263,47 @@ def process(
                                 stripped_line = line.strip().split("#")[0]
                                 import_statement += line
 
-                    cimport_statement: bool = False
                     if (
-                        import_statement.lstrip().startswith(CIMPORT_IDENTIFIERS)
-                        or " cimport " in import_statement
-                        or " cimport*" in import_statement
-                        or " cimport(" in import_statement
-                        or ".cimport" in import_statement
-                    ):
-                        cimport_statement = True
-
-                    if cimport_statement != cimports or (
-                        new_indent != indent
-                        and import_section
-                        and (not did_contain_imports or len(new_indent) < len(indent))
+                        import_statement.lstrip().startswith("from")
+                        and "import" not in import_statement
                     ):
-                        indent = new_indent
-                        if import_section:
-                            next_cimports = cimport_statement
-                            next_import_section = import_statement
-                            import_statement = ""
-                            not_imports = True
-                            line = ""
-                        else:
-                            cimports = cimport_statement
+                        line = import_statement
+                        not_imports = True
                     else:
-                        if new_indent != indent:
-                            if import_section and did_contain_imports:
-                                import_statement = indent + import_statement.lstrip()
+                        did_contain_imports = contains_imports
+                        contains_imports = True
+
+                        cimport_statement: bool = False
+                        if (
+                            import_statement.lstrip().startswith(CIMPORT_IDENTIFIERS)
+                            or " cimport " in import_statement
+                            or " cimport*" in import_statement
+                            or " cimport(" in import_statement
+                            or ".cimport" in import_statement
+                        ):
+                            cimport_statement = True
+
+                        if cimport_statement != cimports or (
+                            new_indent != indent
+                            and import_section
+                            and (not did_contain_imports or len(new_indent) < len(indent))
+                        ):
+                            indent = new_indent
+                            if import_section:
+                                next_cimports = cimport_statement
+                                next_import_section = import_statement
+                                import_statement = ""
+                                not_imports = True
+                                line = ""
                             else:
-                                indent = new_indent
-                    import_section += import_statement
+                                cimports = cimport_statement
+                        else:
+                            if new_indent != indent:
+                                if import_section and did_contain_imports:
+                                    import_statement = indent + import_statement.lstrip()
+                                else:
+                                    indent = new_indent
+                        import_section += import_statement
                 else:
                     not_imports = True
 
diff --git a/isort/parse.py b/isort/parse.py
index 307015e7..714e39ab 100644
--- a/isort/parse.py
+++ b/isort/parse.py
@@ -260,6 +260,7 @@ def file_contents(contents: str, config: Config = DEFAULT_CONFIG) -> ParsedConte
         for statement in statements:
             line, raw_line = _normalize_line(statement)
             type_of_import = import_type(line, config) or ""
+            raw_lines = [raw_line]
             if not type_of_import:
                 out_lines.append(raw_line)
                 continue
@@ -288,6 +289,7 @@ def file_contents(contents: str, config: Config = DEFAULT_CONFIG) -> ParsedConte
                     ):
                         nested_comments[stripped_line] = comments[-1]
                     import_string += line_separator + line
+                    raw_lines.append(line)
             else:
                 while line.strip().endswith("\\"):
                     line, new_comment = parse_comments(in_lines[index])
@@ -310,6 +312,7 @@ def file_contents(contents: str, config: Config = DEFAULT_CONFIG) -> ParsedConte
                         ):
                             nested_comments[stripped_line] = comments[-1]
                         import_string += line_separator + line
+                        raw_lines.append(line)
 
                         while not line.split("#")[0].strip().endswith(")") and index < line_count:
                             line, new_comment = parse_comments(in_lines[index])
@@ -325,6 +328,7 @@ def file_contents(contents: str, config: Config = DEFAULT_CONFIG) -> ParsedConte
                             ):
                                 nested_comments[stripped_line] = comments[-1]
                             import_string += line_separator + line
+                            raw_lines.append(line)
 
                     stripped_line = _strip_syntax(line).strip()
                     if (
@@ -348,6 +352,10 @@ def file_contents(contents: str, config: Config = DEFAULT_CONFIG) -> ParsedConte
                     .replace("\\", " ")
                     .replace("\n", " ")
                 )
+                if "import " not in import_string:
+                    out_lines.extend(raw_lines)
+                    continue
+
                 if " cimport " in import_string:
                     parts = import_string.split(" cimport ")
                     cimports = True