keep track of http related configuration keys.

We also select the most important few for implementation.
The most time-consuming part would be to implement overrides correctly
and validate it against the baseline of git, it's unclear how git
can be queried or made to leak certain information. Maybe by overriding
DNS mappings to let it go against an unknown local IP/port?

Author: Byron

Diff for: git-repository/src/discover.rs

@@ -58,6 +58,10 @@ impl ThreadSafeRepository {
     ///
     /// Finally, use the `trust_map` to determine which of our own repository options to use
     /// based on the trust level of the effective repository directory.
+    // TODO: GIT_HTTP_PROXY_AUTHMETHOD, GIT_PROXY_SSL_CERT, GIT_PROXY_SSL_KEY, GIT_PROXY_SSL_CERT_PASSWORD_PROTECTED.
+    //       GIT_PROXY_SSL_CAINFO, GIT_SSL_VERSION, GIT_SSL_CIPHER_LIST, GIT_HTTP_MAX_REQUESTS, GIT_CURL_FTP_NO_EPSV,
+    //       GIT_HTTP_LOW_SPEED_LIMIT, GIT_HTTP_LOW_SPEED_TIME, GIT_HTTP_USER_AGENT
+    //       The vars above should end up as overrides of the respective configuration values (see git-config).
     pub fn discover_with_environment_overrides_opts(
         directory: impl AsRef<Path>,
         mut options: upwards::Options,

Diff for: src/plumbing/progress.rs

@@ -6,20 +6,18 @@ use tabled::{Style, TableIteratorExt, Tabled};
 
 #[derive(Clone)]
 enum Usage {
-    NotApplicable {
-        reason: &'static str,
-    },
-    NotPlanned {
-        reason: &'static str,
-    },
-    Planned {
-        note: Option<&'static str>,
-    },
+    /// It's not reasonable to implement it as the prerequisites don't apply.
+    NotApplicable { reason: &'static str },
+    /// We have no intention to implement it, but that can change if there is demand.
+    NotPlanned { reason: &'static str },
+    /// We definitely want to implement this configuration value.
+    Planned { note: Option<&'static str> },
+    /// The configuration is already effective and used (at least) in the given module `name`.
     InModule {
         name: &'static str,
         deviation: Option<&'static str>,
     },
-    /// Needs analysis
+    /// Needs analysis, unclear how it works or what it does.
     Puzzled,
 }
 use Usage::*;
@@ -544,6 +542,154 @@ static GIT_CONFIG: &[Record] = &[
         config: "index.version",
         usage: Planned { note: Some("once V4 indices can be written, we need to be able to set a desired version. For now we write the smallest possible index version only.") },
     },
+    Record {
+        config: "http.proxy",
+        usage: Planned { note: None },
+    },
+    Record {
+        config: "http.extraHeader",
+        usage: Planned { note: Some("multi-value, and resettable with empty value") },
+    },
+    Record {
+        config: "http.proxyAuthMethod",
+        usage: Planned { note: None },
+    },
+    Record {
+        config: "http.proxySSLCert",
+        usage: NotPlanned { reason: "on demand" }
+    },
+    Record {
+        config: "http.proxySSLKey",
+        usage: NotPlanned { reason: "on demand" }
+    },
+    Record {
+        config: "http.proxySSLCertPasswordProtected",
+        usage: NotPlanned { reason: "on demand" }
+    },
+    Record {
+        config: "http.proxySSLCAInfo",
+        usage: NotPlanned { reason: "on demand" }
+    },
+    Record {
+        config: "http.emptyAuth",
+        usage: NotPlanned { reason: "on demand" }
+    },
+    Record {
+        config: "http.delegation",
+        usage: NotPlanned { reason: "on demand" }
+    },
+    Record {
+        config: "http.cookieFile",
+        usage: NotPlanned { reason: "on demand" }
+    },
+    Record {
+        config: "http.saveCookies",
+        usage: NotPlanned { reason: "on demand" }
+    },
+    Record {
+        config: "http.version",
+        usage: NotPlanned { reason: "on demand" }
+    },
+    Record {
+        config: "http.curloptResolve",
+        usage: NotPlanned { reason: "on demand" }
+    },
+    Record {
+        config: "http.sslVersion",
+        usage: NotPlanned { reason: "on demand" }
+    },
+    Record {
+        config: "http.sslCipherList",
+        usage: NotPlanned { reason: "on demand" }
+    },
+    Record {
+        config: "http.sslCipherList",
+        usage: NotPlanned { reason: "on demand" }
+    },
+    Record {
+        config: "http.sslVerify",
+        usage: NotPlanned { reason: "on demand" }
+    },
+    Record {
+        config: "http.sslCert",
+        usage: NotPlanned { reason: "on demand" }
+    },
+    Record {
+        config: "http.sslKey",
+        usage: NotPlanned { reason: "on demand" }
+    },
+    Record {
+        config: "http.sslCertPasswordProtected",
+        usage: NotPlanned { reason: "on demand" }
+    },
+    Record {
+        config: "http.sslCertPasswordProtected",
+        usage: NotPlanned { reason: "on demand" }
+    },
+    Record {
+        config: "http.sslCAInfo",
+        usage: NotPlanned { reason: "on demand" }
+    },
+    Record {
+        config: "http.sslCAPath",
+        usage: NotPlanned { reason: "on demand" }
+    },
+    Record {
+        config: "http.sslBackend",
+        usage: NotPlanned { reason: "on demand" }
+    },
+    Record {
+        config: "http.schannelCheckRevoke",
+        usage: NotPlanned { reason: "on demand" }
+    },
+    Record {
+        config: "http.schannelUseSSLCAInfo",
+        usage: NotPlanned { reason: "on demand" }
+    },
+    Record {
+        config: "http.pinnedPubkey",
+        usage: NotPlanned { reason: "on demand" }
+    },
+    Record {
+        config: "http.sslTry",
+        usage: NotPlanned { reason: "on demand" }
+    },
+    Record {
+        config: "http.maxRequests",
+        usage: NotPlanned { reason: "on demand" }
+    },
+    Record {
+        config: "http.minSessions",
+        usage: NotPlanned { reason: "on demand" }
+    },
+    Record {
+        config: "http.postBuffer",
+        usage: Planned { note: Some("relevant when implementing push, we should understand how memory allocation works when streaming") }
+    },
+    Record {
+        config: "http.lowSpeedLimit",
+        usage: Planned { note: Some("important for client-safety when facing bad networks or bad players") }
+    },
+    Record {
+        config: "http.lowSpeedTime",
+        usage: Planned { note: Some("important for client-safety when facing bad networks or bad players") }
+    },
+    Record {
+        config: "http.userAgent",
+        usage: Planned { note: None }
+    },
+    Record {
+        config: "http.noEPSV",
+        usage: NotPlanned { reason: "on demand" }
+    },
+    Record {
+        config: "http.followRedirects",
+        usage: Planned { note: None }
+    },
+    Record {
+        config: "http.<url>.*",
+        usage: Planned { note: Some("it's a vital part of git configuration. It's unclear how to get a baseline from git for this one.") }
+    },
     Record {
         config: "sparse.expectFilesOutsideOfPatterns",
         usage: NotPlanned { reason: "todo" },
@@ -559,7 +705,19 @@ static GIT_CONFIG: &[Record] = &[
         usage: Planned {
             note: Some("required for big monorepos, and typically used in conjunction with sparse indices")
         }
-    }
+    },
+    Record {
+        config: "remote.<name>.proxy",
+        usage: Planned {
+            note: None
+        }
+    },
+    Record {
+        config: "remote.<name>.proxyAuthMethod",
+        usage: Planned {
+            note: None
+        }
+    },
 ];
 
 /// A programmatic way to record and display progress.
@@ -572,7 +730,7 @@ pub fn show_progress() -> anyhow::Result<()> {
 
     println!("{}", sorted.table().with(Style::blank()));
     println!(
-        "\nTotal records: {} ({perfect_icon} = {perfect}, {deviation_icon} = {deviation}, {planned_icon} = {planned})",
+        "\nTotal records: {} ({perfect_icon} = {perfect}, {deviation_icon} = {deviation}, {planned_icon} = {planned}, {ondemand_icon} = {ondemand}, {not_applicable_icon} = {not_applicable})",
         GIT_CONFIG.len(),
         perfect_icon = InModule {
             name: "",
@@ -586,13 +744,23 @@ pub fn show_progress() -> anyhow::Result<()> {
         .icon(),
         planned_icon = Planned { note: None }.icon(),
         planned = GIT_CONFIG.iter().filter(|e| matches!(e.usage, Planned { .. })).count(),
+        ondemand_icon = NotPlanned { reason: "" }.icon(),
+        not_applicable_icon = NotApplicable { reason: "" }.icon(),
         perfect = GIT_CONFIG
             .iter()
             .filter(|e| matches!(e.usage, InModule { deviation, .. } if deviation.is_none()))
             .count(),
         deviation = GIT_CONFIG
             .iter()
             .filter(|e| matches!(e.usage, InModule { deviation, .. } if deviation.is_some()))
+            .count(),
+        ondemand = GIT_CONFIG
+            .iter()
+            .filter(|e| matches!(e.usage, NotPlanned { .. }))
+            .count(),
+        not_applicable = GIT_CONFIG
+            .iter()
+            .filter(|e| matches!(e.usage, NotApplicable { .. }))
             .count()
     );
     Ok(())