libdpkg: Make pkg_name() and pkgbin_name() get const structs

Modifying the struct pkginfo and struct pkgbin complicates how the code
is used, and when the function can be called. Let's just initialize the
pkgname_archqual variable at parse time, so that we can use it at any
time, simplifying the overall code.

4 files changed, 17 insertions, 27 deletions

diff --git a/lib/dpkg/dpkg-db.h b/lib/dpkg/dpkg-db.h
index bffd317ab..56b4b5c39 100644
--- a/lib/dpkg/dpkg-db.h
+++ b/lib/dpkg/dpkg-db.h
@@ -110,8 +110,7 @@ struct pkgbin {
   bool essential;
   enum pkgmultiarch multiarch;
   const struct dpkg_arch *arch;
-  /** The following is the "pkgname:archqual" cached string, if this was a
-   * C++ class this member would be mutable. */
+  /** The fully qualified package name, i.e. "pkgname:archqual". */
   const char *pkgname_archqual;
   const char *description;
   const char *maintainer;
@@ -377,9 +376,9 @@ enum pkg_name_arch_when {
 void varbuf_add_pkgbin_name(struct varbuf *vb, const struct pkginfo *pkg,
                             const struct pkgbin *pkgbin,
                             enum pkg_name_arch_when pnaw);
-const char *pkgbin_name(struct pkginfo *pkg, struct pkgbin *pkgbin,
+const char *pkgbin_name(const struct pkginfo *pkg, const struct pkgbin *pkgbin,
                         enum pkg_name_arch_when pnaw);
-const char *pkg_name(struct pkginfo *pkg, enum pkg_name_arch_when pnaw);
+const char *pkg_name(const struct pkginfo *pkg, enum pkg_name_arch_when pnaw);
 
 void
 pkg_source_version(struct dpkg_version *version,
diff --git a/lib/dpkg/dump.c b/lib/dpkg/dump.c
index b13eb6e79..a04f673d9 100644
--- a/lib/dpkg/dump.c
+++ b/lib/dpkg/dump.c
@@ -461,16 +461,10 @@ writerecord(FILE *file, const char *filename,
 
   varbufrecord(&vb, pkg, pkgbin);
   varbuf_end_str(&vb);
-  if (fputs(vb.buf,file) < 0) {
-    struct varbuf pkgname = VARBUF_INIT;
-    int errno_saved = errno;
 
-    varbuf_add_pkgbin_name(&pkgname, pkg, pkgbin, pnaw_nonambig);
-
-    errno = errno_saved;
+  if (fputs(vb.buf, file) < 0)
     ohshite(_("failed to write details of '%.50s' to '%.250s'"),
-            pkgname.buf, filename);
-  }
+            pkgbin_name(pkg, pkgbin, pnaw_nonambig), filename);
 
   varbuf_destroy(&vb);
 }
diff --git a/lib/dpkg/parse.c b/lib/dpkg/parse.c
index 1b3bf13d8..d75c54458 100644
--- a/lib/dpkg/parse.c
+++ b/lib/dpkg/parse.c
@@ -219,6 +219,16 @@ pkg_parse_verify(struct parsedb_state *ps,
     parse_error(ps, _("package has field '%s' but is architecture all"),
                 "Multi-Arch: same");
 
+  /* Generate the fully qualified package name representation. */
+  if (pkgbin->arch->type != DPKG_ARCH_NONE &&
+      pkgbin->arch->type != DPKG_ARCH_EMPTY) {
+    char *pkgname = nfmalloc(strlen(pkg->set->name) + 1 +
+                             strlen(pkgbin->arch->name) + 1);
+
+    str_concat(pkgname, pkg->set->name, ":", pkgbin->arch->name, NULL);
+    pkgbin->pkgname_archqual = pkgname;
+  }
+
   /* Initialize deps to be arch-specific unless stated otherwise. */
   for (dep = pkgbin->depends; dep; dep = dep->next)
     for (dop = dep->list; dop; dop = dop->next)
diff --git a/lib/dpkg/pkg-show.c b/lib/dpkg/pkg-show.c
index 6af658c42..4818675bb 100644
--- a/lib/dpkg/pkg-show.c
+++ b/lib/dpkg/pkg-show.c
@@ -93,25 +93,12 @@ varbuf_add_pkgbin_name(struct varbuf *vb,
  * @return The string representation.
  */
 const char *
-pkgbin_name(struct pkginfo *pkg, struct pkgbin *pkgbin,
+pkgbin_name(const struct pkginfo *pkg, const struct pkgbin *pkgbin,
             enum pkg_name_arch_when pnaw)
 {
 	if (!pkgbin_name_needs_arch(pkgbin, pnaw))
 		return pkg->set->name;
 
-	/* Cache the package name representation, for later reuse. */
-	if (pkgbin->pkgname_archqual == NULL) {
-		struct varbuf vb = VARBUF_INIT;
-
-		varbuf_add_str(&vb, pkg->set->name);
-		varbuf_add_archqual(&vb, pkgbin->arch);
-		varbuf_end_str(&vb);
-
-		pkgbin->pkgname_archqual = nfstrsave(vb.buf);
-
-		varbuf_destroy(&vb);
-	}
-
 	return pkgbin->pkgname_archqual;
 }
 
@@ -126,7 +113,7 @@ pkgbin_name(struct pkginfo *pkg, struct pkgbin *pkgbin,
  * @return The string representation.
  */
 const char *
-pkg_name(struct pkginfo *pkg, enum pkg_name_arch_when pnaw)
+pkg_name(const struct pkginfo *pkg, enum pkg_name_arch_when pnaw)
 {
 	return pkgbin_name(pkg, &pkg->installed, pnaw);
 }