Trim readme lines in linear time

The heading pattern backtracked over a run of spaces in cubic time and
the cell trim in quadratic time, so one crafted line in a readme could
hold a request for half an hour, well inside the size cap. The heading
rule now also keeps a sharp that ends a word, as in "# C#".

1 file changed, 10 insertions, 0 deletions

diff --git a/tests/extensions/test-about-render.lua b/tests/extensions/test-about-render.luaindex 338949a..b0379b7 100644--- a/tests/extensions/test-about-render.lua+++ b/tests/extensions/test-about-render.lua@@ -73,6 +73,9 @@ h.contains("a heading renders inside the wrapper", out, "<div class='markdown'>< out = render("README.md", "## Sub ##") h.contains("trailing hashes are stripped from a heading", out, "<h2>Sub</h2>") +out = render("README.md", "# C#")+h.contains("a hash ending a word stays in the heading", out, "<h1>C#</h1>")+ out = render("README.MD", "# Upper") h.contains("the extension matches whatever its case", out, "<h1>Upper</h1>") @@ -160,6 +163,13 @@ h.contains("the innermost text still renders", out, "x") out = render("README.md", string.rep("*a", 200)) h.check("an emphasis bomb still renders something", #out > 0) +-- Trimming a run of spaces must stay linear, or one hostile line holds a+-- request for minutes. Both lines below took seconds before.+local started = os.clock()+render("README.md", "# a" .. string.rep(" ", 3000) .. "b")+render("README.md", "| a | b |\n|---|---|\n| x" .. string.rep(" ", 40000) .. "y | z |")+h.check("a long run of spaces is trimmed quickly", os.clock() - started < 1)+ out = render("README.md", "| a | b |\n| --- | --- |\n| 1 | 2 |") h.contains("a pipe table renders its head", out, "<thead><tr><th>a</th><th>b</th></tr></thead>") h.contains("a pipe table renders its body", out, "<tbody><tr><td>1</td><td>2</td></tr></tbody>")
diff --git a/tests/extensions/test-about-render.lua b/tests/extensions/test-about-render.lua
index 338949a..b0379b7 100644
--- a/tests/extensions/test-about-render.lua
+++ b/tests/extensions/test-about-render.lua
@@ -73,6 +73,9 @@ h.contains("a heading renders inside the wrapper", out, "<div class='markdown'><
 out = render("README.md", "## Sub ##")
 h.contains("trailing hashes are stripped from a heading", out, "<h2>Sub</h2>")
 
+out = render("README.md", "# C#")
+h.contains("a hash ending a word stays in the heading", out, "<h1>C#</h1>")
+
 out = render("README.MD", "# Upper")
 h.contains("the extension matches whatever its case", out, "<h1>Upper</h1>")
 
@@ -160,6 +163,13 @@ h.contains("the innermost text still renders", out, "x")
 out = render("README.md", string.rep("*a", 200))
 h.check("an emphasis bomb still renders something", #out > 0)
 
+-- Trimming a run of spaces must stay linear, or one hostile line holds a
+-- request for minutes. Both lines below took seconds before.
+local started = os.clock()
+render("README.md", "# a" .. string.rep(" ", 3000) .. "b")
+render("README.md", "| a | b |\n|---|---|\n| x" .. string.rep(" ", 40000) .. "y | z |")
+h.check("a long run of spaces is trimmed quickly", os.clock() - started < 1)
+
 out = render("README.md", "| a | b |\n| --- | --- |\n| 1 | 2 |")
 h.contains("a pipe table renders its head", out, "<thead><tr><th>a</th><th>b</th></tr></thead>")
 h.contains("a pipe table renders its body", out, "<tbody><tr><td>1</td><td>2</td></tr></tbody>")