Move dupcat out into its own file, and add dupstr.

Also a handy #define to replace all those tedious castings of NULL.

Makefile.am

@@ -5,10 +5,10 @@ ACLOCAL_AMFLAGS = -I m4
 lib_LTLIBRARIES = libwinterop.so.la libmsi.so.la libpreload.la
 
 libwinterop_so_la_SOURCES = fake-winterop.c fake-lib.c fake-lib.h	\
-memory.c memory.h
+memory.c memory.h dupstr.c dupstr.h
 
 libmsi_so_la_SOURCES = fake-msi.c fake-lib.c fake-lib.h md5.c	\
-memory.c memory.h version.c
+memory.c memory.h version.c dupstr.c dupstr.h
 
 libpreload_la_SOURCES = preload.c
 libpreload_la_LDFLAGS = -ldl

dupstr.c

@@ -0,0 +1,35 @@
+#include <stdarg.h>
+#include <string.h>
+
+#include "memory.h"
+#include "dupstr.h"
+
+char *dupcat(const char *str, ...)
+{
+    va_list ap;
+    const char *p;
+    char *out, *outp;
+    size_t len;
+
+    len = 1;
+    va_start(ap, str);
+    for (p = str; p; p = va_arg(ap, const char *))
+        len += strlen(p);
+    va_end(ap);
+
+    out = snewn(len, char);
+    outp = out;
+    va_start(ap, str);
+    for (p = str; p; p = va_arg(ap, const char *)) {
+        strcpy(outp, p);
+        outp += strlen(p);
+    }
+    va_end(ap);
+
+    return out;
+}
+
+char *dupstr(const char *str)
+{
+    return dupcat(str, (const char *)NULL);
+}

dupstr.h

@@ -0,0 +1,6 @@
+#include <stddef.h>
+
+#define cNULL ((const char *)NULL)
+
+char *dupstr(const char *str);
+char *dupcat(const char *str, ...);

fake-lib.c

@@ -88,28 +88,3 @@ void c16cpy(char16_t *out, uint32_t *outsize, char *s)
     }
     *outsize = retlen;
 }
-
-char *dupcat(const char *str, ...)
-{
-    va_list ap;
-    const char *p;
-    char *out, *outp;
-    size_t len;
-
-    len = 1;
-    va_start(ap, str);
-    for (p = str; p; p = va_arg(ap, const char *))
-        len += strlen(p);
-    va_end(ap);
-
-    out = snewn(len, char);
-    outp = out;
-    va_start(ap, str);
-    for (p = str; p; p = va_arg(ap, const char *)) {
-        strcpy(outp, p);
-        outp += strlen(p);
-    }
-    va_end(ap);
-
-    return out;
-}

fake-lib.h

@@ -5,4 +5,3 @@ char *ascii(const char16_t *wstr, bool translate_slashes);
 void system_argv(const char *cmd, ...);
 void system_argv_array(char **args);
 void c16cpy(char16_t *out, uint32_t *outsize, char *s);
-char *dupcat(const char *str, ...);

fake-msi.c

@@ -15,6 +15,7 @@
 #include <unistd.h>
 
 #include "memory.h"
+#include "dupstr.h"
 #include "fake-lib.h"
 
 typedef struct MsiTypePrefix {
@@ -42,19 +43,18 @@ uint32_t MsiOpenDatabaseW(const char16_t *filename,
     close(open(ctx->outfile, O_CREAT | O_WRONLY, 0666));
     ctx->outfile = realpath(ctx->outfile, NULL);
     unlink(ctx->outfile);
-    ctx->tempdir = dupcat(ctx->outfile, "-msiXXXXXX", (const char *)NULL);
+    ctx->tempdir = dupcat(ctx->outfile, "-msiXXXXXX", cNULL);
     if (!mkdtemp(ctx->tempdir))
         err(1, "%s: mkdtemp", ctx->tempdir);
     ctx->nargs = 0;
     ctx->argsize = 16;
     ctx->args = snewn(ctx->argsize, char *);
-    ctx->args[ctx->nargs++] = dupcat("sh", (const char *)NULL);
+    ctx->args[ctx->nargs++] = dupstr("sh");
-    ctx->args[ctx->nargs++] = dupcat("-c", (const char *)NULL);
+    ctx->args[ctx->nargs++] = dupstr("-c");
-    ctx->args[ctx->nargs++] = dupcat("cd \"$0\" && \"$@\"",
+    ctx->args[ctx->nargs++] = dupstr("cd \"$0\" && \"$@\"");
-                                     (const char *)NULL);
+    ctx->args[ctx->nargs++] = dupstr(ctx->tempdir);
-    ctx->args[ctx->nargs++] = dupcat(ctx->tempdir, (const char *)NULL);
+    ctx->args[ctx->nargs++] = dupstr("msibuild");
-    ctx->args[ctx->nargs++] = dupcat("msibuild", (const char *)NULL);
+    ctx->args[ctx->nargs++] = dupstr(ctx->outfile);
-    ctx->args[ctx->nargs++] = dupcat(ctx->outfile, (const char *)NULL);
     *out_ctx = ctx;
     return 0;
 }
@@ -64,15 +64,14 @@ uint32_t MsiDatabaseImportW(MsiMainCtx *ctx, const char16_t *folder,
 {
     assert(ctx->t.type == MAIN);
     system_argv("sh", "-c", "cd \"$0\" && cp \"$1\" \"$2\"",
-                ascii(folder, true), ascii(file, true), ctx->tempdir,
+                ascii(folder, true), ascii(file, true), ctx->tempdir, cNULL);
-                (const char *)NULL);
     if (ctx->nargs + 2 >= ctx->argsize) {
         ctx->argsize = ctx->nargs * 5 / 4 + 16;
         ctx->args = sresize(ctx->args, ctx->argsize, char *);
     }
-    ctx->args[ctx->nargs++] = dupcat("-i", (const char *)NULL);
+    ctx->args[ctx->nargs++] = dupstr("-i");
     ctx->args[ctx->nargs++] = dupcat(ctx->tempdir, "/", ascii(file, true),
-                                     (const char *)NULL);
+                                     cNULL);
     return 0;
 }
 
@@ -96,15 +95,13 @@ uint32_t MsiDatabaseOpenViewW(MsiMainCtx *ctx, const char16_t *query,
         view->fp = NULL;               /* special case */
     else {
         if (!strcmp(cquery, "SELECT  `Name`, `Data` FROM `Binary`")) {
-            view->fp = fopen(dupcat(ctx->tempdir, "/", "Binary.idt",
+            view->fp = fopen(dupcat(ctx->tempdir, "/", "Binary.idt", cNULL),
-                                    (const char *)NULL), "a");
+                             "a");
-            view->targetdir = dupcat(ctx->tempdir, "/", "Binary",
+            view->targetdir = dupcat(ctx->tempdir, "/", "Binary", cNULL);
-                                     (const char *)NULL);
         } else if (!strcmp(cquery, "SELECT  `Name`, `Data` FROM `Icon`")) {
-            view->fp = fopen(dupcat(ctx->tempdir, "/", "Icon.idt",
+            view->fp = fopen(dupcat(ctx->tempdir, "/", "Icon.idt", cNULL),
-                                    (const char *)NULL), "a");
+                             "a");
-            view->targetdir = dupcat(ctx->tempdir, "/", "Icon",
+            view->targetdir = dupcat(ctx->tempdir, "/", "Icon", cNULL);
-                                     (const char *)NULL);
         } else
             errx(1, "unrecognised query: %s", cquery);
         if (!view->fp)
@@ -163,8 +160,7 @@ uint32_t MsiViewModify(MsiView *view, uint32_t mode, MsiRecord *rec)
     assert(rec->t.type == RECORD);
     if (view->fp) {
         system_argv("sh", "-c", "cp \"$0\" \"$1\"/\"$2\"",
-                    rec->data, view->targetdir, rec->name,
+                    rec->data, view->targetdir, rec->name, cNULL);
-                    (const char *)NULL);
         fprintf(view->fp, "%s\t%s\r\n", rec->name, rec->name);
     } else {
         MsiMainCtx *ctx = view->ctx;
@@ -172,9 +168,9 @@ uint32_t MsiViewModify(MsiView *view, uint32_t mode, MsiRecord *rec)
             ctx->argsize = ctx->nargs * 5 / 4 + 16;
             ctx->args = sresize(ctx->args, ctx->argsize, char *);
         }
-        ctx->args[ctx->nargs++] = dupcat("-a", (const char *)NULL);
+        ctx->args[ctx->nargs++] = dupstr("-a");
-        ctx->args[ctx->nargs++] = dupcat(rec->name, (const char *)NULL);
+        ctx->args[ctx->nargs++] = dupstr(rec->name);
-        ctx->args[ctx->nargs++] = dupcat(rec->data, (const char *)NULL);
+        ctx->args[ctx->nargs++] = dupstr(rec->data);
     }
     return 0;
 }

fake-winterop.c

@@ -12,6 +12,7 @@
 #include <unistd.h>
 
 #include "memory.h"
+#include "dupstr.h"
 #include "fake-lib.h"
 
 uint32_t HashPublicKeyInfo(void *pCertContext,
@@ -41,13 +42,11 @@ uint32_t CreateCabBegin(const char16_t *wzCab, const char16_t *wzCabDir,
 {
     CabCreateContext *ctx = snew(CabCreateContext);
     ctx->outdir = ascii(wzCabDir, true);
-    ctx->outfile = dupcat(ctx->outdir, "/",
+    ctx->outfile = dupcat(ctx->outdir, "/", ascii(wzCab, true), cNULL);
-                          ascii(wzCab, true), (const char *)NULL);
     ctx->nargs = 0;
     ctx->argsize = 16;
     ctx->args = snewn(ctx->argsize, char *);
-    ctx->args[ctx->nargs++] = dupcat(getenv("WIX"), "/", "makecab.py",
+    ctx->args[ctx->nargs++] = dupcat(getenv("WIX"), "/", "makecab.py", cNULL);
-                                     (const char *)NULL);
     ctx->args[ctx->nargs++] = ctx->outfile;
     *out_ctx = ctx;
     return 0;
@@ -104,7 +103,7 @@ uint32_t ExtractCab(const char16_t *wzCabinet, const char16_t *wzExtractDir)
 {
     char *cab = ascii(wzCabinet, true), *dir = ascii(wzExtractDir, true);
     fprintf(stderr, "ExtractCab(\"%s\", \"%s\"\n", cab, dir);
-    system_argv("cabextract", "-d", dir, cab, (const char *)NULL);
+    system_argv("cabextract", "-d", dir, cab, cNULL);
     return 0;
 }