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authorEelco Dolstra <edolstra@gmail.com>2017-07-11T21·20+0200
committerEelco Dolstra <edolstra@gmail.com>2017-07-11T21·21+0200
commit2965d40612e16388ef2177d2a13d168848c6ca8a (patch)
tree71bc2ff5c9ca7860d4c32793940ee5fb557767b9 /src/libutil
parent8e8caf7f3e535d4e397f422f6c0effd81f497305 (diff)
replaceSymlink(): Handle the case where the temporary file already exists
Not really necessary anymore for #849, but still nice to have.
Diffstat (limited to 'src/libutil')
-rw-r--r--src/libutil/util.cc17
1 files changed, 13 insertions, 4 deletions
diff --git a/src/libutil/util.cc b/src/libutil/util.cc
index 6bf4b3d91805..d9f8011b6fb9 100644
--- a/src/libutil/util.cc
+++ b/src/libutil/util.cc
@@ -496,12 +496,21 @@ void createSymlink(const Path & target, const Path & link)
 
 void replaceSymlink(const Path & target, const Path & link)
 {
-    Path tmp = canonPath(dirOf(link) + "/.new_" + baseNameOf(link));
+    for (unsigned int n = 0; true; n++) {
+        Path tmp = canonPath(fmt("%s/.%d_%s", dirOf(link), n, baseNameOf(link)));
 
-    createSymlink(target, tmp);
+        try {
+            createSymlink(target, tmp);
+        } catch (SysError & e) {
+            if (e.errNo == EEXIST) continue;
+            throw;
+        }
 
-    if (rename(tmp.c_str(), link.c_str()) != 0)
-        throw SysError(format("renaming ‘%1%’ to ‘%2%’") % tmp % link);
+        if (rename(tmp.c_str(), link.c_str()) != 0)
+            throw SysError(format("renaming ‘%1%’ to ‘%2%’") % tmp % link);
+
+        break;
+    }
 }