Ticket #36: 02_ifexists_else_endif.dpatch

#! /bin/sh /usr/share/dpatch/dpatch-run
## 02_ifexists_else_endif.dpatch by CJ van den Berg <cj@vdbonline.com>
##
## All lines beginning with `## DP:' are a description of the patch.
## DP: add support for .ifexists, .else and .endif meta commands

@DPATCH@

diff -Nru pulseaudio-0.9.5-orig/src/pulsecore/cli-command.c pulseaudio-0.9.5/src/pulsecore/cli-command.c
--- pulseaudio-0.9.5-orig/src/pulsecore/cli-command.c   2006-08-19 18:25:38.000000000 +0200
+++ pulseaudio-0.9.5/src/pulsecore/cli-command.c    2006-10-06 02:08:00.446876784 +0200
@@ -28,6 +28,7 @@
 #include <assert.h>
 #include <stdlib.h>
 #include <errno.h>
+#include <unistd.h>
 
 #include <pulse/xmalloc.h>
 
@@ -63,6 +64,13 @@
 #define INCLUDE_META ".include"
 #define FAIL_META ".fail"
 #define NOFAIL_META ".nofail"
+#define IFEXISTS_META ".ifexists"
+#define ELSE_META ".else"
+#define ENDIF_META ".endif"
+
+#define IFSTATE_NONE 0
+#define IFSTATE_TRUE 1
+#define IFSTATE_FALSE 2
 
 /* Prototypes for all available commands */
 static int pa_cli_command_exit(pa_core *c, pa_tokenizer *t, pa_strbuf *buf, int *fail);
@@ -953,7 +961,7 @@
     return 0;
 }
 
-int pa_cli_command_execute_line(pa_core *c, const char *s, pa_strbuf *buf, int *fail) {
+int pa_cli_command_execute_line_stateful(pa_core *c, const char *s, pa_strbuf *buf, int *fail, int *ifstate) {
     const char *cs;
     
     cs = s+strspn(s, whitespace);
@@ -961,6 +969,25 @@
     if (*cs == '#' || !*cs)
         return 0;
     else if (*cs == '.') {
+        if (!strcmp(cs, ELSE_META)) {
+            if (!ifstate || *ifstate == IFSTATE_NONE) {
+                pa_strbuf_printf(buf, "Meta command %s is not valid in this context\n", cs);
+                return -1;
+            } else if (*ifstate == IFSTATE_TRUE)
+                *ifstate = IFSTATE_FALSE;
+            else
+                *ifstate = IFSTATE_TRUE;
+            return 0;
+        } else if (!strcmp(cs, ENDIF_META)) {
+            if (!ifstate || *ifstate == IFSTATE_NONE) {
+                pa_strbuf_printf(buf, "Meta command %s is not valid in this context\n", cs);
+                return -1;
+            } else
+                *ifstate = IFSTATE_NONE;
+            return 0;
+        }
+        if (ifstate && *ifstate == IFSTATE_FALSE)
+            return 0;
         if (!strcmp(cs, FAIL_META))
             *fail = 1;
         else if (!strcmp(cs, NOFAIL_META))
@@ -974,6 +1001,21 @@
 
                 if (pa_cli_command_execute_file(c, filename, buf, fail) < 0)
                     if (*fail) return -1;
+            } else if (l == sizeof(IFEXISTS_META)-1 && !strncmp(cs, IFEXISTS_META, l)) {
+                if (!ifstate) {
+                    pa_strbuf_printf(buf, "Meta command %s is not valid in this context\n", cs);
+                    return -1;
+                } else if (*ifstate != IFSTATE_NONE) {
+                    pa_strbuf_printf(buf, "Nested %s commands not supported\n", cs);
+                    return -1;
+                } else {
+                    const char *filename = cs+l+strspn(cs+l, whitespace);
+
+                    if (access(filename, F_OK) == 0)
+                        *ifstate = IFSTATE_TRUE;
+                    else
+                        *ifstate = IFSTATE_FALSE;
+                }
             } else {
                 pa_strbuf_printf(buf, "Invalid meta command: %s\n", cs);
                 if (*fail) return -1;
@@ -984,6 +1026,9 @@
         int unknown = 1;
         size_t l;
         
+        if (ifstate && *ifstate == IFSTATE_FALSE)
+            return 0;
+
         l = strcspn(cs, whitespace);
 
         for (command = commands; command->name; command++) 
@@ -1011,9 +1056,14 @@
     return 0;
 }
 
+int pa_cli_command_execute_line(pa_core *c, const char *s, pa_strbuf *buf, int *fail) {
+    return pa_cli_command_execute_line_stateful(c, s, buf, fail, NULL);
+}
+
 int pa_cli_command_execute_file(pa_core *c, const char *fn, pa_strbuf *buf, int *fail) {
     char line[256];
     FILE *f = NULL;
+    int ifstate = IFSTATE_NONE;
     int ret = -1;
     assert(c && fn && buf);
 
@@ -1028,7 +1078,7 @@
         char *e = line + strcspn(line, linebreak);
         *e = 0;
 
-        if (pa_cli_command_execute_line(c, line, buf, fail) < 0 && *fail)
+        if (pa_cli_command_execute_line_stateful(c, line, buf, fail, &ifstate) < 0 && *fail)
             goto fail;
     }