Merge pull request #5108 from quarto-dev/bugfix/5089-2

Improved fix for 5089

Author: dragonstyle

src/resources/filters/common/url.lua

@@ -12,4 +12,13 @@ function urldecode(url)
   return url
 end
 
-
+function fullyUrlDecode(url)
+  -- decode the url until it is fully decoded (not a single pass,
+  -- but repeated until it decodes no further)
+  result = urldecode(url)
+  if result == url then
+    return result
+  else 
+    return fullyUrlDecode(result)
+  end
+end

src/resources/filters/quarto-post/pdf-images.lua

@@ -20,6 +20,19 @@ local function convert_svg(path)
   end
 end
 
+local mimeImgExts = {
+  ["image/jpeg"]="jpg",
+  ["image/gif"]="gif",
+  ["image/vnd.microsoft.icon"]="ico",
+  ["image/avif"]="avif",
+  ["image/bmp"]="bmp",
+  ["image/png"]="png",
+  ["image/svg+xml"]="svg",
+  ["image/tiff"]="tif",
+  ["image/webp"]="webp",
+}
+
+
 -- A cache of image urls that we've resolved into the mediabag
 -- keyed by {url: mediabagpath}
 local resolvedUrls = {}
@@ -109,13 +122,31 @@ function pdfImages()
             else 
               local relativePath = image.src:match('https?://[%w%.%:]+/(.+)')
               if relativePath then
-                
+
                 local imgMt, imgContents = pandoc.mediabag.fetch(image.src)
-                local decodedSrc = urldecode(image.src)
+                local decodedSrc = fullyUrlDecode(image.src)                
                 if decodedSrc == nil then
                   decodedSrc = "unknown"
                 end
-                local filename = windows_safe_filename(tex_safe_filename(pandoc.path.filename(decodedSrc)))
+
+                local function filenameFromMimeType(filename, imgMt)
+                  -- Use the mime type to compute an extension when possible
+                  -- This will allow pandoc to properly know the type, even when 
+                  -- the path to the image is a difficult to parse URI
+                  local mimeExt = mimeImgExts[imgMt]
+                  if mimeExt then
+                    local stem, _ext = pandoc.path.split_extension(filename)
+                    return stem .. '.' .. mimeExt
+                  else
+                    return filename
+                  end
+                end
+
+                -- compute the filename for this file
+                local basefilename = pandoc.path.filename(decodedSrc)
+                local safefilename = windows_safe_filename(tex_safe_filename(basefilename))
+                local filename = filenameFromMimeType(safefilename, imgMt)
+
                 if imgMt ~= nil then
                   local existingMt = pandoc.mediabag.lookup(filename)
                   local counter = 1
@@ -139,3 +170,4 @@ function pdfImages()
   }
 end
 
+

tests/docs/smoke-all/2023/04/04/5089.qmd

@@ -7,7 +7,6 @@ format: pdf
 
 ![](https://substackcdn.com/image/fetch/f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fbucketeer-e05bbc84-baa3-437e-9518-adb32be77984.s3.amazonaws.com%2Fpublic%2Fimages%2F9b7345d9-5f62-46dc-8062-d704c2c014a5_289x174.jpeg)
 
-
 ## Simple Url
 
 ![](https://quarto.org/quarto.png)