Fix: Preserve newlines in code blocks with github flavor

Commit 7c4daaf introduced a workaround for GitHub-flavored markdown treating
newlines as <br/> in paragraphs by unconditionally replacing all \n with
spaces when markdown_flavor='github'. However, this broke code blocks,
doctest blocks, and math blocks where newlines are semantically significant.

The visit_literal_block method already sets escape_text=False to signal
verbatim contexts. This fix conditions the newline replacement on
escape_text=True, so newlines are only collapsed in prose paragraphs,
not in code/math/comment blocks.

Impact: Multi-line argparse usage text (e.g., from sphinxcontrib-autoprogram)
now renders correctly with proper line breaks instead of collapsing into
a single line with multiple spaces.

Added test case with multi-line code block to prevent regression.

Signed-off-by: Eike Waldt <waldt@b1-systems.de>
On-behalf-of: SAP <eike.waldt@sap.com>

Author: yeoldegrove

sphinx_markdown_builder/translator.py

@@ -346,7 +346,7 @@ def visit_image(self, node):
     def visit_Text(self, node):  # pylint: disable=invalid-name
         text = node.astext().replace("\r", "")
         # Replace line breaks with spaces to create single-line paragraphs
-        if self.config.markdown_flavor == "github":
+        if self.config.markdown_flavor == "github" and self.status.escape_text:
             text = text.replace("\n", " ")
         if self.status.escape_text:
             text = escape_markdown_chars(text)

tests/source/blocks.rst

@@ -23,6 +23,16 @@ Code Example
 >>> print("this is a Doctest block.")
 this is a Doctest block.
 
+Multi-line Code Block
+---------------------
+
+.. code-block:: console
+
+   usage: command [-h] [--option1 VALUE1]
+                  [--option2 VALUE2]
+                  [--option3 VALUE3]
+                  argument
+
 
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