From 2ff7c1f41b52921c3abea46ded8714b4fd9698b4 Mon Sep 17 00:00:00 2001
From: Nathan Phillip Brink <binki@gentoo.org>
Date: Mon, 13 Jul 2015 00:32:32 +0000
Subject: [PATCH] Convert compiletime ID Anchor setting to runtime flag for
 issue #124.

Now specify flag `-fidanchor` or `MKD_IDANCHOR` instead of
`./configure.sh --with-id-anchor`. In `markdown -VV` displays as
`IDANCHOR` or `!IDANCHOR` rather than `ID-ANCHOR`.
---
 configure.sh  |  4 +---
 flags.c       |  1 +
 generate.c    | 38 +++++++++++++++++++-------------------
 markdown.1    |  2 ++
 markdown.3    |  2 ++
 markdown.h    |  1 +
 mkdio.h.in    |  1 +
 pgm_options.c |  1 +
 tests/toc.t   | 49 ++++++++++++++++++++++++-------------------------
 version.c.in  |  3 ---
 10 files changed, 52 insertions(+), 50 deletions(-)

diff --git a/configure.sh b/configure.sh
index 17e98ae2..93c96a9c 100755
--- a/configure.sh
+++ b/configure.sh
@@ -9,7 +9,6 @@
 #
 ac_help='--enable-amalloc	Enable memory allocation debugging
 --with-tabstops=N	Set tabstops to N characters (default is 4)
---with-id-anchor	Use id= anchors for table-of-contents links
 --with-github-tags	Allow `_` and `-` in <> tags
 --with-urlencoded-anchor	Use url-encoded chars to multibyte chars in toc links
 --enable-all-features	Turn on all stable optional features
@@ -46,14 +45,13 @@ TARGET=markdown
 
 AC_INIT $TARGET
 
-for banned_with in dl fenced-code; do
+for banned_with in dl fenced-code id-anchor; do
     banned_with_variable_ref=\$WITH_`echo "$banned_with" | $AC_UPPERCASE | tr - _`
     if [ "`eval echo "$banned_with_variable_ref"`" ]; then
 	AC_FAIL "Invalid option: --with-$banned_with. Please use a runtime flag to configure this feature."
     fi
 done
 
-test "$WITH_ID_ANCHOR" && AC_DEFINE 'WITH_ID_ANCHOR' 1
 test "$WITH_GITHUB_TAGS" && AC_DEFINE 'WITH_GITHUB_TAGS' 1
 test "$WITH_URLENCODED_ANCHOR" && AC_DEFINE 'WITH_URLENCODED_ANCHOR' 1
 test "$DEBIAN_GLITCH" && AC_DEFINE 'DEBIAN_GLITCH' 1
diff --git a/flags.c b/flags.c
index cb7221aa..53717d54 100644
--- a/flags.c
+++ b/flags.c
@@ -33,6 +33,7 @@ static struct flagnames flagnames[] = {
     { MKD_NODLDISCOUNT,   "!DLDISCOUNT" },
     { MKD_DLEXTRA,        "DLEXTRA" },
     { MKD_FENCEDCODE,     "FENCEDCODE" },
+    { MKD_IDANCHOR,       "IDANCHOR" },
 };
 #define NR(x)	(sizeof x/sizeof x[0])
 
diff --git a/generate.c b/generate.c
index 6573fc49..a91949ea 100644
--- a/generate.c
+++ b/generate.c
@@ -1426,26 +1426,26 @@ text(MMIOT *f)
 static void
 printheader(Paragraph *pp, MMIOT *f)
 {
-#if WITH_ID_ANCHOR
-    Qprintf(f, "<h%d", pp->hnumber);
-    if ( f->flags & MKD_TOC ) {
-	Qstring(" id=\"", f);
-	mkd_string_to_anchor(T(pp->text->text),
-			     S(pp->text->text),
-			     (mkd_sta_function_t)Qchar, f, 1);
-	Qchar('"', f);
-    }
-    Qchar('>', f);
-#else
-    if ( f->flags & MKD_TOC ) {
-	Qstring("<a name=\"", f);
-	mkd_string_to_anchor(T(pp->text->text),
-			     S(pp->text->text),
-			     (mkd_sta_function_t)Qchar, f, 1);
-	Qstring("\"></a>\n", f);
+    if ( f->flags & MKD_IDANCHOR ) {
+	Qprintf(f, "<h%d", pp->hnumber);
+	if ( f->flags & MKD_TOC ) {
+	    Qstring(" id=\"", f);
+	    mkd_string_to_anchor(T(pp->text->text),
+				 S(pp->text->text),
+				 (mkd_sta_function_t)Qchar, f, 1);
+	    Qchar('"', f);
+	}
+	Qchar('>', f);
+    } else {
+	if ( f->flags & MKD_TOC ) {
+	    Qstring("<a name=\"", f);
+	    mkd_string_to_anchor(T(pp->text->text),
+				 S(pp->text->text),
+				 (mkd_sta_function_t)Qchar, f, 1);
+	    Qstring("\"></a>\n", f);
+	}
+	Qprintf(f, "<h%d>", pp->hnumber);
     }
-    Qprintf(f, "<h%d>", pp->hnumber);
-#endif
     push(T(pp->text->text), S(pp->text->text), f);
     text(f);
     Qprintf(f, "</h%d>", pp->hnumber);
diff --git a/markdown.1 b/markdown.1
index bdbcc1af..b31ab096 100644
--- a/markdown.1
+++ b/markdown.1
@@ -121,6 +121,8 @@ Allow markdown extra-style footnotes.
 Extract <style> blocks from the output.
 .It Ar fencedcode
 Allow fenced code blocks (not default).
+.It Ar idanchor
+Use id= anchors for table-of-contents links instead of <a name=/> (not default).
 .El
 .Pp
 As an example, the option
diff --git a/markdown.3 b/markdown.3
index 71831c7a..9e9ac5c5 100644
--- a/markdown.3
+++ b/markdown.3
@@ -114,6 +114,8 @@ Enable markdown extra-style footnotes.
 Do not extract (omit) <style/> blocks from the output.
 .It Ar MKD_FENCEDCODE
 Allow fenced code blocks.
+.It Ar MKD_IDANCHOR
+Use id= anchors instead of <a name=/> for table-of-contents links.
 .El
 .Sh RETURN VALUES
 .Fn markdown
diff --git a/markdown.h b/markdown.h
index b8d17397..51ed602c 100644
--- a/markdown.h
+++ b/markdown.h
@@ -132,6 +132,7 @@ typedef struct mmiot {
 #define MKD_NODLDISCOUNT 0x00800000
 #define	MKD_DLEXTRA	0x01000000
 #define MKD_FENCEDCODE	0x02000000
+#define MKD_IDANCHOR	0x04000000
 #define IS_LABEL	0x08000000
 #define USER_FLAGS	0x0FFFFFFF
 #define INPUT_MASK	(MKD_NOHEADER|MKD_TABSTOP)
diff --git a/mkdio.h.in b/mkdio.h.in
index 46ebe064..51ba87fe 100644
--- a/mkdio.h.in
+++ b/mkdio.h.in
@@ -109,6 +109,7 @@ void mkd_ref_prefix(MMIOT*, char*);
 #define MKD_NODLDISCOUNT 0x00800000	/* disable discount-style definition lists */
 #define	MKD_DLEXTRA	0x01000000	/* enable extra-style definition lists */
 #define MKD_FENCEDCODE	0x02000000	/* enabled fenced code blocks */
+#define MKD_IDANCHOR	0x04000000	/* use id= anchors for TOC links */
 
 #define MKD_EMBED	MKD_NOLINKS|MKD_NOIMAGE|MKD_TAGTEXT
 
diff --git a/pgm_options.c b/pgm_options.c
index 3dad63b6..d25bfe5a 100644
--- a/pgm_options.c
+++ b/pgm_options.c
@@ -58,6 +58,7 @@ static struct _opt {
     { "dldiscount",    "discount-style definition lists", 1, 0, 1, MKD_NODLDISCOUNT },
     { "dlextra",       "extra-style definition lists", 0, 0, 1, MKD_DLEXTRA },
     { "fencedcode",    "fenced code blocks",         0, 0, 1, MKD_FENCEDCODE },
+    { "idanchor",      "id= anchors in TOC",         0, 0, 1, MKD_IDANCHOR },
 } ;
 
 #define NR(x)	(sizeof x / sizeof x[0])
diff --git a/tests/toc.t b/tests/toc.t
index 7f6057af..59f39129 100644
--- a/tests/toc.t
+++ b/tests/toc.t
@@ -4,14 +4,13 @@
 rc=0
 MARKDOWN_FLAGS=
 
-if ./markdown -V | grep ID-ANCHOR >/dev/null; then
-    # old-style; uses id= tag (and collides
-    # with #-style css)
-
-    title "(old) table-of-contents support"
-    
-    try '-T -ftoc' 'table of contents' \
-    '#H1
+# old-style; uses id= tag (and collides
+# with #-style css)
+
+title "(old) table-of-contents support"
+
+try -fidanchor '-T -ftoc' 'table of contents' \
+'#H1
 hi' \
 '<ul>
  <li><a href="#H1">H1</a></li>
@@ -20,8 +19,8 @@ hi' \
 
 <p>hi</p>'
 
-    try '-T -ftoc' 'toc item with link' \
-    '##[H2](H2) here' \
+try -fidanchor '-T -ftoc' 'toc item with link' \
+'##[H2](H2) here' \
 '<ul>
  <li>
  <ul>
@@ -31,21 +30,22 @@ hi' \
 </ul>
 <h2 id="H2.here"><a href="H2">H2</a> here</h2>'  
 
-    try '-T -ftoc' 'toc item with non-alpha start' \
-    '#1 header' \
+try -fidanchor '-T -ftoc' 'toc item with non-alpha start' \
+'#1 header' \
 '<ul>
  <li><a href="#L1.header">1 header</a></li>
 </ul>
 <h1 id="L1.header">1 header</h1>'
 
-else
-    # new-style; uses a (depreciated) name=
-    # inside a null <a> tag
-    
-    title "(new) table-of-contents support"
-    
-    try '-T -ftoc' 'table of contents' \
-    '#H1
+summary $0
+
+# new-style; uses a (depreciated) name=
+# inside a null <a> tag
+
+title "(new) table-of-contents support"
+
+try '-T -ftoc' 'table of contents' \
+'#H1
 hi' \
 '<ul>
  <li><a href="#H1">H1</a></li>
@@ -55,8 +55,8 @@ hi' \
 
 <p>hi</p>'
 
-    try '-T -ftoc' 'toc item with link' \
-    '##[H2](H2) here' \
+try '-T -ftoc' 'toc item with link' \
+'##[H2](H2) here' \
 '<ul>
  <li>
  <ul>
@@ -67,14 +67,13 @@ hi' \
 <a name="H2.here"></a>
 <h2><a href="H2">H2</a> here</h2>'  
 
-    try '-T -ftoc' 'toc item with non-alpha start' \
-    '#1 header' \
+try '-T -ftoc' 'toc item with non-alpha start' \
+'#1 header' \
 '<ul>
  <li><a href="#L1.header">1 header</a></li>
 </ul>
 <a name="L1.header"></a>
 <h1>1 header</h1>'
-fi
 
 summary $0
 exit $rc
diff --git a/version.c.in b/version.c.in
index a4664739..1166419a 100644
--- a/version.c.in
+++ b/version.c.in
@@ -7,9 +7,6 @@ char markdown_version[] = VERSION
 #if USE_AMALLOC
 		" DEBUG"
 #endif
-#if WITH_ID_ANCHOR
-		" ID-ANCHOR"
-#endif
 #if WITH_GITHUB_TAGS
 		" GITHUB-TAGS"
 #endif