Add support for uncompressing gzipped man pages.
If the requested page does not exist, try to serve gzipped one instead (closes: #418771).

diff -ruN -x '*.rej' -x '*.orig' man-1.6e-old/man2html/Makefile.in man-1.6e/man2html/Makefile.in
--- man-1.6e-old/man2html/Makefile.in	2007-04-16 23:16:14.000000000 +0200
+++ man-1.6e/man2html/Makefile.in	2007-04-16 22:55:37.000000000 +0200
@@ -1,4 +1,4 @@
-CFLAGS += -Wall -Wstrict-prototypes -Wmissing-prototypes $(DEBIAN_CFLAGS)
+CFLAGS += -Wall -Wstrict-prototypes -Wmissing-prototypes -DGUNZIP='"@gunzip@"' $(DEBIAN_CFLAGS)
 OBJECTS = man2html.o cgibase.o abbrev.o strdefs.o
 bindir = $(DESTDIR)$(PREFIX)/usr/bin
 mandir = $(DESTDIR)$(PREFIX)@mandir@
diff -ruN -x '*.rej' -x '*.orig' man-1.6e-old/man2html/man2html.c man-1.6e/man2html/man2html.c
--- man-1.6e-old/man2html/man2html.c	2007-04-16 23:16:15.000000000 +0200
+++ man-1.6e/man2html/man2html.c	2007-04-16 23:17:33.000000000 +0200
@@ -15,6 +15,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
+#include <errno.h>
 #include <stdarg.h>
 #include <string.h>
 #include <ctype.h>
@@ -57,6 +58,108 @@
 
 static char charb[3];
 
+#ifdef GUNZIP	
+/* from src/utils.c */
+static int
+is_shell_safe(const char *ss, int quoted) {
+	char *bad = " ;'\\\"<>|";
+	char *p;
+
+	if (quoted)
+		bad++;			/* allow a space inside quotes */
+	for (p = bad; *p; p++)
+		if (strchr(ss, *p))
+			return 0;
+	return 1;
+}
+#endif
+
+/* reads the entire manpage into buffer *buf and returns number of chars read */
+static int
+read_manpage_into_buffer(char *path, char **buf) {
+	int compressed = 0;
+	FILE * f = NULL;
+	char * ext;
+	int l = 0;
+	struct stat stbuf;
+	
+	*buf = NULL;
+	if (!path) 
+		return -1;
+		
+	if (!strcmp(path, "-")) 
+		f = stdin;
+	else /* strcmp(path, "-") */
+	{
+		char * tmp = NULL;
+		char * command = NULL;
+		char * openpath = path;
+#ifdef GUNZIP	
+
+		if (is_shell_safe(openpath, 1)) {
+			ext = strrchr(openpath, '.');
+			compressed = (ext && !strcmp(ext, ".gz"));
+		
+			if (!compressed && stat(openpath, &stbuf)) {
+				tmp = (char*) xmalloc(strlen(path) + 4);
+				sprintf(tmp, "%s.gz", path);
+				if ((compressed = !stat(tmp, &stbuf)))
+					openpath = tmp; 		
+			}
+		}		
+
+		if (compressed) {
+			command = (char*) xmalloc(strlen(openpath) + sizeof(GUNZIP) + 4);
+			sprintf(command, GUNZIP " '%s'", openpath);
+			f = popen(command, "r");
+		} else
+#endif
+			f = fopen(openpath, "r");
+
+		if (tmp) free(tmp);
+		if (command) free(command);
+		
+		if (!f)
+			return -1;
+		
+	} /* strcmp(path, "-") */
+
+
+    /* Read entire file into buf[1..l] */
+#define XTRA 5
+    /* buf has 1 extra byte at the start, and XTRA extra bytes at the end */
+    if (compressed || f == stdin) {
+	 int sz = 1024;
+	 int ct = 1, tot = 0;
+	 char *p = NULL;
+
+	 clearerr(f);
+	 while (ct > 0) {
+	      tot += ct;
+	      if (feof(f))
+		   break;
+	      sz = 2*sz+tot;
+	      p = xrealloc(p, sz);
+	      ct = fread(p+tot,1,sz-tot-XTRA,f);
+	 }
+
+	 *buf = p;
+	 l = tot-1;
+    } else {
+	 int ct;
+
+	 l = 0;
+	 if (fstat(fileno(f), &stbuf) != -1)
+	      l = stbuf.st_size;
+	 *buf = (char *) xmalloc((l+1+XTRA)*sizeof(char));
+	 ct = fread(*buf+1,1,l,f);
+	 if (ct < l)
+	      l = ct;
+    }
+   fclose(f);
+   return l;    
+}
+
 static char *
 expand_char(int nr)
 {
@@ -1841,8 +1944,6 @@
 	    break;
 	case V('s','o'):
 	    {
-		FILE *f;
-		struct stat stbuf;
 		int l; char *buf;
 		char *name = NULL;
 
@@ -1850,21 +1951,21 @@
 		c += j;			/* skip .so part and whitespace */
 		if (*c == '/') {
 		    h = c;
-		} else {		/* .so man3/cpow.3 -> ../man3/cpow.3 */
-		    h = c-3;
-		    h[0] = '.';
-		    h[1] = '.';
-		    h[2] = '/';
-		}
+               } else {                /* .so man3/cpow.3 -> ../man3/cpow.3 */
+/*                   h = c-3;
+                   h[0] = '.';
+                   h[1] = '.';
+                   h[2] = '/';
+*/		   
+		   h = c;
+               }
+
 		while (*c != '\n') c++;
 		while (c[-1] == ' ') c--;
 		while (*c != '\n') *c++ = 0;
 		*c = 0;
 		scan_troff(h,1, &name);
 		if (name[3] == '/') h=name+3; else h=name;
-		l = 0;
-		if (stat(h, &stbuf)!=-1) l=stbuf.st_size;
-		buf = (char*) xmalloc((l+4)*sizeof(char));
 #if NOCGI
                 if (!out_length) {
 		    char *t,*s;
@@ -1882,7 +1983,7 @@
 #endif
                 {
 		    /* this works alright, except for section 3 */
-		    if (!l || !(f = fopen(h,"r"))) {
+		    if ((l = read_manpage_into_buffer(h, &buf)) < 0) {
 			 fprintf(stderr,
 				"man2html: unable to open or read file %s\n", h);
 			 out_html("<BLOCKQUOTE>"
@@ -1890,13 +1991,11 @@
 			 out_html(h);
 			 out_html("</BLOCKQUOTE>\n");
 		    } else {
-			i=fread(buf+1,1,l,f);
-			fclose(f);
 			buf[0]=buf[l]='\n';
 			buf[l+1]=buf[l+2]=0;
 			scan_troff(buf+1,0,NULL);
+		    	if (buf) free(buf);
 		    }
-		    if (buf) free(buf);
 		}
 		*c++='\n';
 		break;
@@ -3140,6 +3239,8 @@
      }
 }
 
+
+
 /*
  * Call:  man2html [-l] [filename]
  *
@@ -3150,8 +3251,6 @@
  */
 int
 main(int argc, char **argv) {
-    FILE *f;
-    struct stat stbuf;
     int l, c;
     char *buf, *filename, *fnam = NULL;
 
@@ -3213,50 +3312,17 @@
 
     /* Open input file */
     if (!fnam || !strcmp(fnam, "-")) {
-	 f = stdin;
+	 fnam = "-";
 	 fname = "(stdin)";
     } else {
 	 /* do a chdir() first, to get .so expansion right */
 	 goto_dir(fnam, &directory, &fnam);
-
-	 f = fopen(fnam, "r");
-	 if (f == NULL)
-	      error_page(404, "File not found", "Could not open %s\n", filename);
 	 fname = fnam;
     }
 
-    /* Read entire file into buf[1..l] */
-#define XTRA 5
-    /* buf has 1 extra byte at the start, and XTRA extra bytes at the end */
-    if (f == stdin) {
-	 int sz = 1024;
-	 int ct = 1, tot = 0;
-	 char *p = NULL;
-
-	 clearerr(stdin);
-	 while (ct > 0) {
-	      tot += ct;
-	      if (feof(stdin))
-		   break;
-	      sz = 2*sz+tot;
-	      p = xrealloc(p, sz);
-	      ct = fread(p+tot,1,sz-tot-XTRA,stdin);
-	 }
-
-	 buf = p;
-	 l = tot-1;
-    } else {
-	 int ct;
-
-	 l = 0;
-	 if (fstat(fileno(f), &stbuf) != -1)
-	      l = stbuf.st_size;
-	 buf = (char *) xmalloc((l+1+XTRA)*sizeof(char));
-	 ct = fread(buf+1,1,l,f);
-	 if (ct < l)
-	      l = ct;
-	 fclose(f);
-    }
+    l = read_manpage_into_buffer(fnam, &buf);
+    if (l < 0)
+    	error_page(404, "File not found", "Could not open %s\n", fname);
 
     buf[0] = '\n';
     buf[l+1] = '\n';