entities: support ' entity

The XHTML standard encompasses the XML standard.

From the beginning, the XML standard [1] has always included required
support for five character entities:

 1. the ampersand (&) as &
 2. the left angle bracket (<) as &lt;
 3. the right angle bracket (>) as &gt;
 4. the double-quote character (") as &quot;
 5. the apostrophe or single-quote character (') as &apos;

See section "2.4 Character Data and Markup" of the XML standard [1]
for further details.

Add support for the character single-quote character entity (&apos;)
in order to fully support XHTML pages.

[1]: https://www.w3.org/TR/REC-xml/

Signed-off-by: Kyle J. McKay <mackyle@gmail.com>

3 files changed, 6 insertions, 4 deletions

diff --git a/entity.tab b/entity.tab
index 130ae2d..d481312 100644
--- a/entity.tab
+++ b/entity.tab
@@ -7,6 +7,8 @@ amp	0x26
 AMP	0x26
 quot	0x22
 QUOT	0x22
+apos	0x27
+APOS	0x27
 nbsp	0xA0
 NBSP	0xA0
 iexcl	0xA1
diff --git a/indep.c b/indep.c
index 5c5de06..4957c67 100644
--- a/indep.c
+++ b/indep.c
@@ -19,7 +19,7 @@ unsigned char QUOTE_MAP[0x100] = {
     /* DLE DC1 DC2 DC3 DC4 NAK SYN ETB CAN  EM SUB ESC  FS  GS  RS  US */
     24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
     /* SPC   !   "   #   $   %   &   '   (   )   *   +   ,   -   .   / */
-    24, 72, 76, 40, 8, 40, 41, 72, 72, 72, 72, 40, 72, 8, 0, 64,
+    24, 72, 76, 40, 8, 40, 41, 77, 72, 72, 72, 40, 72, 8, 0, 64,
     /*   0   1   2   3   4   5   6   7   8   9   :   ;   <   =   >   ? */
     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 32, 72, 74, 72, 75, 40,
     /*   @   A   B   C   D   E   F   G   H   I   J   K   L   M   N   O */
@@ -47,7 +47,7 @@ char *HTML_QUOTE_MAP[] = {
     "&lt;",
     "&gt;",
     "&quot;",
-    NULL,
+    "&apos;",
     NULL,
     NULL,
 };
@@ -462,7 +462,7 @@ getescapechar(char **str)
     q = p;
     for (p++; IS_ALNUM(*p); p++) ;
     q = allocStr(q, p - q);
-    if (strcasestr("lt gt amp quot nbsp", q) && *p != '=') {
+    if (strcasestr("lt gt amp quot apos nbsp", q) && *p != '=') {
 	/* a character entity MUST be terminated with ";". However,
 	 * there's MANY web pages which uses &lt , &gt or something
 	 * like them as &lt;, &gt;, etc. Therefore, we treat the most
diff --git a/indep.h b/indep.h
index 2809832..5c6b1da 100644
--- a/indep.h
+++ b/indep.h
@@ -27,7 +27,7 @@ struct growbuf {
 
 extern unsigned char QUOTE_MAP[];
 extern char *HTML_QUOTE_MAP[];
-#define HTML_QUOTE_MASK   0x07	/* &, <, >, " */
+#define HTML_QUOTE_MASK   0x07	/* &, <, >, ", ' */
 #define SHELL_UNSAFE_MASK 0x08	/* [^A-Za-z0-9_./:\200-\377] */
 #define URL_QUOTE_MASK    0x10	/* [\0- \177-\377] */
 #define FILE_QUOTE_MASK   0x30	/* [\0- #%&+:?\177-\377] */