Use alt text title if description is blank or missing

3 files changed, 71 insertions, 6 deletions

diff --git a/NEWS b/NEWS
index b5b3451..b3c8205 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,8 @@
+# 1.2.0
+
+* Use alt text title as alt text for images when the alt text description is
+  blank or missing.
+  
 # 1.1.1
 
 * Handle comments without author initials.
diff --git a/mammoth/docx/body_xml.py b/mammoth/docx/body_xml.py
index b1be2e5..fbf813c 100644
--- a/mammoth/docx/body_xml.py
+++ b/mammoth/docx/body_xml.py
@@ -269,7 +269,11 @@ def _create_reader(numbering, content_types, relationships, styles, docx_file, f
             return _success(documents.line_break())
     
     def inline(element):
-        alt_text = element.find_child_or_null("wp:docPr").attributes.get("descr")
+        properties = element.find_child_or_null("wp:docPr").attributes
+        if properties.get("descr", "").strip():
+            alt_text = properties.get("descr")
+        else:
+            alt_text = properties.get("title")
         blips = element.find_children("a:graphic") \
             .find_children("a:graphicData") \
             .find_children("pic:pic") \
diff --git a/tests/docx/body_xml_tests.py b/tests/docx/body_xml_tests.py
index 6064ddb..678d17f 100644
--- a/tests/docx/body_xml_tests.py
+++ b/tests/docx/body_xml_tests.py
@@ -464,6 +464,56 @@ class ReadXmlElementTests(object):
         with image.open() as image_file:
             assert_equal(self.IMAGE_BYTES, image_file.read())
         
+        
+    @istest
+    def alt_text_title_is_used_if_alt_text_description_is_blank(self):
+        drawing_element = _create_inline_image(
+            blip=_embedded_blip(self.IMAGE_RELATIONSHIP_ID),
+            description=" ",
+            title="It's a hat",
+        )
+        
+        image = self._read_embedded_image(drawing_element)
+        
+        assert_equal(documents.Image, type(image))
+        assert_equal("It's a hat", image.alt_text)
+        assert_equal("image/png", image.content_type)
+        with image.open() as image_file:
+            assert_equal(self.IMAGE_BYTES, image_file.read())
+        
+        
+    @istest
+    def alt_text_title_is_used_if_alt_text_description_is_missing(self):
+        drawing_element = _create_inline_image(
+            blip=_embedded_blip(self.IMAGE_RELATIONSHIP_ID),
+            title="It's a hat",
+        )
+        
+        image = self._read_embedded_image(drawing_element)
+        
+        assert_equal(documents.Image, type(image))
+        assert_equal("It's a hat", image.alt_text)
+        assert_equal("image/png", image.content_type)
+        with image.open() as image_file:
+            assert_equal(self.IMAGE_BYTES, image_file.read())
+        
+        
+    @istest
+    def alt_text_description_is_preferred_to_alt_text_title(self):
+        drawing_element = _create_inline_image(
+            blip=_embedded_blip(self.IMAGE_RELATIONSHIP_ID),
+            description="It's a hat",
+            title="hat",
+        )
+        
+        image = self._read_embedded_image(drawing_element)
+        
+        assert_equal(documents.Image, type(image))
+        assert_equal("It's a hat", image.alt_text)
+        assert_equal("image/png", image.content_type)
+        with image.open() as image_file:
+            assert_equal(self.IMAGE_BYTES, image_file.read())
+        
     @istest
     def can_read_anchored_pictures(self):
         drawing_element = _create_anchored_image(
@@ -696,21 +746,27 @@ def _text_element(value):
     return xml_element("w:t", {}, [xml_text(value)])
     
 
-def _create_inline_image(description, blip):
+def _create_inline_image(blip, description=None, title=None):
     return xml_element("w:drawing", {}, [
-        xml_element("wp:inline", {}, _create_image_elements(description, blip))
+        xml_element("wp:inline", {}, _create_image_elements(blip, description=description, title=title))
     ])
 
 
 def _create_anchored_image(description, blip):
     return xml_element("w:drawing", {}, [
-        xml_element("wp:anchor", {}, _create_image_elements(description, blip))
+        xml_element("wp:anchor", {}, _create_image_elements(blip, description=description, ))
     ])
 
     
-def _create_image_elements(description, blip):
+def _create_image_elements(blip, description=None, title=None):
+    properties = {}
+    if description is not None:
+        properties["descr"] = description
+    if title is not None:
+        properties["title"] = title
+    
     return [
-        xml_element("wp:docPr", {"descr": description}),
+        xml_element("wp:docPr", properties),
         xml_element("a:graphic", {}, [
             xml_element("a:graphicData", {}, [
                 xml_element("pic:pic", {}, [